US10999656B2 - Coherent gigabit ethernet and passive optical network coexistence in optical communications module link extender related systems and methods - Google Patents

Abstract

This disclosure describes devices and methods related to multiplexing optical data signals. A method may be disclosed for multiplexing one or more optical data signals. The method may comprise receiving, by a dense wave division multiplexer (DWDM), one or more optical data signals. The method may comprise combining, by the DWDM, the one or more optical data signals. The method may comprise outputting, by the DWDM, the combined one or more optical data signals to one or more wave division multiplexer (WDM). The method may comprise combining, by the one or more WDM, the combined one or more optical data signals and one or more second optical data signals, and outputting an egress optical data signal comprising the combined one or more optical data signals and one or more second optical data signals.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION

The present application is related to and claims priority from U.S. patent application Ser. No. 16/054,737 filed Mar. 8, 2018, which claims priority from U.S. patent application Ser. No. 15/877,247 field Jan. 22, 2018, which is a conversion of U.S. Provisional Patent Application No. 62/448,663 filed Jan. 20, 2017, and U.S. Provisional Patent Application No. 62/536,431 filed Jul. 24, 2017, the disclosures of which are incorporated by reference as set forth in full.

FIELD OF INVENTION

This disclosure relates generally to the field of optical telecommunications and includes an integrated module with several sub-assemblies.

BACKGROUND

To understand the importance of optical networking, the capabilities of this technology have to be discussed in the context of the challenges faced by the telecommunications industry, and, in particular, service providers. Most U.S. networks were built using estimates that calculated bandwidth use by employing concentration ratios derived from classical engineering formulas for modeling network usage such as the Poisson process. Consequently, forecasts of the amount of bandwidth capacity needed for data networks were calculated on the presumption that a given individual would only use network bandwidth six minutes of each hour. These formulas did not factor in the amount of traffic generated by different devices accessing the Internet. With the advent of the Internet and the ever increasing number of devices (e.g., facsimile machines, multiple phone lines, modems, teleconferencing equipment, mobile devices including smart phones, tablets, laptops, wearable devices, and Internet of Things (IoT) devices, etc.) accessing the Internet, there has been an average increase in Internet traffic of 300 percent year over year. Had these factors been included, a far different estimate would have emerged.

As a result of this explosive growth of devices, an enormous amount of bandwidth capacity is required to provide the services required by these devices. In the 1990s, some long-distance carriers increased their capacity (bandwidth) to 1.2 Gbps over a single optical fiber pair, which was a considerable upgrade at the time. At a transmission speed of one Gbps, one thousand books can be transmitted per second. However today, if one million families in a city decided to view a video on a Web site (e.g., YouTube, Home Box Office (HBO) on the go, DirectTV, etc.) then network transmission rates on the order of terabits are required. With a transmission rate of one terabit, it is possible to transmit 200 million simultaneous full duplex phone calls or transmit the text from 300 years-worth of daily newspapers per second.

When largescale data networks providing residential, commercial, and enterprise customers with Internet access were first deployed, the unprecedented growth in the number of devices accessing the network could not have been imagined. As a result, the network growth requirements needed in order to meet the demand of the devices were not considered at that time either. For example, from 1994 to 1998, it is estimated that the demand on the U.S. interexchange carriers' (IXC's) network would increase sevenfold, and for the U.S. local exchange carriers' (LEC's) network, the demand would increase fourfold. For instance, some cable companies indicated that their network growth was 32 times the previous year, while other cable companies have indicated that the size of their networks have doubled every six months in a four-year period.

In addition to this explosion in consumer demand for bandwidth, many service provider are coping with optical fiber exhaust in their network. For example, in 1995 alone many Internet Service Provider (ISP) companies indicated that the amount of embedded optical fibers already in use at the time was between 70 percent and 80 percent (i.e., 70 to 80 percent of the capacity of their networks were used the majority of the time to provide service to customers). Today, many cable companies are nearing one hundred percent capacity utilization across significant portions of their networks. Another problem for cable companies is the challenge of deploying and integrating diverse technologies in on physical infrastructure. Customer demands and competitive pressures mandate that carriers offer diverse services economically and deploy them over the embedded network. One potential technology that meets these requirements is based on multiplexing a large and diverse number of data, regardless of the type of data, onto a beam of light that may be attenuated to propagate at different wavelengths. The different types of data may comprise facsimile sources, landline voice sources, voice over Internet Protocol (VOIP) sources, video sources, web browser sources, mobile device sources including voice application sources, short messaging service (SMS) application sources, multimedia messaging service (MMS) application sources, mobile phone third party application (app) sources, and/or wearable device sources. When a large and diverse number of data sources, such as the ones mentioned in the previous sentence, are multiplexed together over light beams transmitted on an optical fiber, it may be referred to as a dense wave division multiplexing (DWDM).

The use of an optical communications module link extender (OCML) circuit as described herein allows cable companies to offer these services regardless of the open systems interconnection (OSI) model network layer (layer 3) protocols or media access control (MAC) (layer 2) protocols that are used by the different sources to transmit data. For example, e-mail, video, and/or multimedia data such as web based content data, may generate IP (layer 3) data packets that are transmitted in asynchronous transfer mode (ATM) (layer 2) frames. Voice (telephony) data may be transmitted over synchronous optical networking (SONET)/synchronous digital hierarchy (SDH). Therefore regardless of which layer is generating data (e.g., IP, ATM, and/or SONET/SDH) a DWDM passive circuit provides unique bandwidth management by treating all data the same. This unifying capability allows cable companies with the flexibility to meet customer demands over a self-contained network.

A platform that is able to unify and interface with these technologies and position the cable company with the ability to integrate current and next-generation technologies is critical for a cable company's success.

Cable companies faced with the multifaceted challenge of increased service needs, optical fiber exhaust, and layered bandwidth management, need options to provide economical and scalable technologies. One way to alleviate optical fiber exhaust is to lay more optical fiber, and, for those networks where the costs of laying new optical fiber is minimal, the best solution may be to lay more optical fiber. This solution may work in more rural, where there may be no considerable population growth. However, in urban or suburban areas laying new optical fiber may be costly. Even if it was not costly, the mere fact that more cable is being laid does not necessarily enable a cable company to provide new services or utilize the bandwidth management capabilities of the unifying optical transmission mechanism such as DWDM.

Another solution may be to increase the bit rate using time division multiplexing (TDM). TDM increases the capacity of an optical fiber by slicing time into smaller time intervals so that more bits of data can be transmitted per second. Traditionally, this solution has been the method of choice, and cable companies have continuously upgraded their networks using different types of digital signaling technologies to multiplex data over SONET/SDH networks. For example, Digital Signal (DS) DS-1, DS-2, DS-3, DS-4, and DS-5, commonly referred to as T1, T2, T3, T4, or T5 lines, are different carrier signals, that are transmitted over SONET/SDH networks that can carry any of the sources of data mentioned above, whose data rates increase with the number assigned to the DS. That is DS-1 was the earliest carrier signal used to transmit data over SONET/SDH networks, and has the lowest data rate and DS-5 is the most recent carrier signal use to transmit data over SONET/SDH networks with the highest data rate. Cable company networks, especially SONET/SDH networks have evolved over time to increase the number of bits of data that can be transmitted per second by using carrier signals with higher data rates. However, when cable companies use this approach, they must purchase capacity based on what the SONET/SDH standard dictates will be the next increase in capacity. For example, cable companies can purchase a capacity of 10 Gbps for TDM, but should the capacity not be enough the cable companies will have to purchase a capacity of 40 Gbps for TDM, because there are no intermediate amounts of capacity for purchase. In such a situation, a cable company may purchase a significant amount of capacity that they may not use, and that could potentially cost them more than they are willing to pay to meet the needs of their customers. Furthermore, with TDM based SONET/SDH networks, the time intervals can only be reduced to a certain size beyond which it is no longer possible to increase the capacity of a SONET/SDH network. For instance, increasing the capacity of SONET/SDH networks to 40 Gbps using TDM technology may prove to be extremely difficult to achieve in the future.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a schematic of an Optical Communications Module Link (OCML) Extender, in accordance with the disclosure.

FIG. 2 depicts an network architecture, in accordance with the disclosure.

FIG. 3 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 4 shows an access link loss budget of a Dense Wave Division Multiplexing (DWDM) passive circuit, in accordance with the disclosure.

FIG. 5 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 6 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 7 depicts different passive optical network (PON) transceiver parameters associated with downstream transmitting circuits and upstream transmitting circuits, in accordance with the disclosure.

FIG. 8 depicts a graphical representation of wavelengths used to transport one or more signals, in accordance with the disclosure.

FIG. 9 a stimulated Raman scattering (SRS) diagram, in accordance with the disclosure.

FIG. 10 depicts a schematic illustration of wavelength and optical fiber monitoring of cascaded OCML headends in accordance with the disclosure.

FIG. 11 a schematic illustration of wavelength and optical fiber monitoring of an OCML headend in accordance with the disclosure.

FIG. 12 depicts an access network diagram of an OCML headend comprising wavelength division multiplexers (WDMs), a dense wavelength division multiplexer (DWDM), and optical amplifiers, in accordance with the disclosure.

FIG. 13 depicts an access network diagram of an OCML headend comprising WDMs, a DWDM, optical amplifiers, and dispersion control modules (DCMs), in accordance with the disclosure.

FIG. 14 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 15 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 16 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 17A depicts an access network diagram of an OCML headend, in accordance with the disclosure.

FIG. 17B depicts an access network diagram of a multiplexer-demultiplexer (MDM), in accordance with the disclosure.

FIG. 18 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.

FIG. 19 depicts a process of transmitting optical signals with the OCML headend, in accordance with the disclosure.

FIG. 20 depicts a process of transmitting optical signals with the OCML headend, in accordance with the disclosure.

FIG. 21 depicts an aggregation node, in accordance with the disclosure.

DETAILED DESCRIPTION

DWDM passive circuits can be used in combination with one or more other optical communications devices to develop novel signal extension circuits that increase the range with which light beams are propagated and the number of signals that can be combined and transmitted from a cable company to customers. The circuits disclosed herein may be referred to Optical Communications Module Link (OCML) Extender. The OCML passive circuits, disclosed herein, increase the capacity of embedded optical fibers by first assigning incoming optical signals to specific frequencies (wavelength, denoted by lambda) within a designated frequency band and then multiplexing the resulting signals out onto one optical fiber. Because incoming signals are never terminated in the optical layer, the interface can be bit-rate and format independent, thereby allowing the service provider to integrate DWDM passive circuits easily into a passive circuit, such as an OCML passive circuit, with existing equipment in the network while gaining access to the untapped capacity in the embedded optical fibers.

A DWDM passive circuit combines multiple optical signals for transportation over a single optical fiber, thereby increasing the capacity of a service provider's network. Each signal carried can be at a different rate (e.g., optical carrier transmission rate OC-3, OC-12, OC-24 etc.) and in a different format (e.g., SONET, ATM, data, etc.). For example, the networks disclosed herein comprise DWDM passive circuits that transmit and receive a mix of SONET signals with different data rates (e.g., OC-48 signals with a data rate of 2.5 Gbps or OC-192 signals with a data rate of 10 Gbps) can achieve data rates (capacities) of over 40 Gbps. The OCML passive circuits disclosed herein can achieve the aforementioned while maintaining the same degree of system performance, reliability, and robustness as current transport systems—or even surpassing it. The OCML passive circuits may be a smart platform, integrated into a network headend or a network cabinet, and may connect a metro area network that provides internet and telecommunications services to end users (e.g., enterprise multi dwelling unit (MDU) customers, residential customers, commercial customers, and industrial customers) via one or more optical fiber links. The OCML passive circuits may also be referred to as OCML headends. The OCML headend enables a plurality of signals to be cost effectively transported over long optical fiber distances between 5 km and 60 km without having to put any optical amplifiers or other active devices, like an optical switch, (which is normally used to provide path redundancy in case of an optical fiber cut) in the field.

The OCML headend is intended to transport a mix of multi-wavelength coherent 10G non-return-to-zero (NRZ), coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON signals over the same optical fiber without having active devices such as optical amplifiers in the field. The OCML headend is also configured to support the same wavelengths over a secondary optical fiber via an optical switch in case the primary optical fiber experiences a cut. In one embodiment, an OCML headend, systems, and methods include various subsystems integrated into a single module including an integrated DWDM passive circuit that combines and separates bi-directional wavelengths in optical fibers propagating in a conventional wavelength window, such as the c band dispersive region of the optical fibers. The OCML headend may comprise a three port or four port wave division multiplexer (WDM) or circulator to combine and separate 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream and upstream signals of different wavelengths. The OCML headend may also comprise a four port WDM to combine GPON, EPON, and 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical signals of different wavelengths, whereas the DWDM combines SONSET/SDH and/or ATM signals. The OCML headend may also comprise a five port WDM to combine and separate upstream and downstream signals comprising GPON, XGPON/10GEPON, and 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals of different wavelengths. Although the term multiplexer is used to describe the WDMs as disclosed herein, the WDMs do not exclusively multiplex (combine) one or more downstream signals into a single downstream signal, but they also demultiplex (separate) a single upstream signal into one or more upstream signals.

The WDM may comprise one or more thin film filters (TFFs) or array waveguide gratings (AWGs) that combine one or more downstream signals into a single downstream signal and separate a single upstream signal into one or more upstream signals. The WDM may comprise one or more wavelength-converting transponders, wherein each of the wavelength-converting transponders receives an optical data signal (e.g., a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal) from a client-layer optical network such as, for example, a Synchronous optical network (SONET)/synchronous digital hierarchy (SDH), Internet protocol (IP), and/or asynchronous transfer mode (ATM) optical network. Each of the wavelength-converting transponders converts the optical data signal into an electrical data signal, and then converts the electrical data signal into a second optical data signal to be emitted by a laser, wherein the second optical data signal is carried by one or more packets of light oscillating with wavelengths in the c band. More specifically, each of the wavelength-converting transponders may include a laser that emits the second optical data signal. That is each of the second optical data signals may be emitted by a laser with a unique wavelength. In some embodiments, the wavelength-converting transponders may comprise two adjacent transceivers. That is, each of the wavelength-converting transponders may comprise a first transceiver that converts the optical data signal into an electrical data signal, and may comprise second transceiver that converts the electrical data signal into the second optical data signal. The second transceiver converts the electrical signal to the second optical data signal such that the second optical data signal is transmitted with the correct wavelength.

A first wavelength-converting transponder, of the two wavelength-converting transponders, may emit a second optical data signal with a 1550 nm wavelength. A second wavelength-converting transponder, of the two wavelength-converting transponders, may emit a second optical data signal with a 1533 nm wavelength. For example, there may be two wavelength-converting transponders, and each of the two wavelength-converting transponders may include a laser emitting a second optical data signal with a unique wavelength. Thus, each of the wavelength-converting transponders converts the electrical data signal into an optical data signal, and each of the wavelength-converting transponders emits, or transmits, the optical data signal, with a wavelength in the c band, to a TFF or AWG. The TFF or AWG, may combine or multiplex the optical data signals, emitted by each of the wavelength-converting transponders, into a multi-wavelength optical data signal wherein each of the wavelengths in the multi-wavelength optical data signal coincide with the wavelengths associated with each of the optical data signals. Returning to the example above of the two wavelength-converting transponders, the first and second wavelength-converting transponders, may each receive an optical signal from a SONET/SDH client layer network. The first and second wavelength-converting transponders may each respectively convert the optical signal they received from the SONET/SDH client layer network into an electrical data signal. The first wavelength-converting transponder may convert the electrical data signal that it receives into a second optical data signal with a first wavelength. The first wavelength-converting transponder may emit, via a first laser, the second optical data signal, with the first wavelength, to the TFF or AWG. The second wavelength-converting transponder may convert the electrical data signal that it receives into a second optical data signal with a second wavelength. The second wavelength-converting transponder may emit, via a second laser, the second optical signal, with the second wavelength, to the TFF or AWG. The TFF or AWG may combine or multiplex the second optical data signal, with the first wavelength, and the second optical data signal, with the second wavelength, onto a multi-wavelength optical signal. The TFF or AWG may be referred to as an optical multiplexer.

The DWDM passive circuits disclosed herein may include wavelength-converting transponders and corresponding WDMs that combine or multiplex optical data signals similar to the WDMs described above. The DWDM passive circuits may also include wavelength-converting transponders and corresponding WDMs that separate optical data signals. In some embodiments, the same WDM may combine optical data signals and separate optical data signals. That is, the WDM may separate one or more optical data signals from a multi-wavelength optical data signal, or demultiplex the one or more optical data signals from the multi-wavelength optical data signal. The WDM may separate the one or more optical data signals from a multi-wavelength optical data signal using a process that is the exact opposite of the process used to combine one or more optical data signals into a multi-wavelength signal. The WDM may separate one or more optical data signals from a multi-wavelength optical data signal that may correspond to an upstream signal received from a remote DWDM passive circuit.

The WDM may receive the multi-wavelength optical data signal and one or more TTF or AWGs may separate the one or more optical data signals, from the multi-wavelength optical data signal, using filters or waveguide gratings with properties that separate optical data signals, with different wavelengths, from a multi-wavelength optical data signal. After the WDM has separated the optical data signals, with different wavelengths, from the multi-wavelength optical data signal, the WDM may convert each of the separated optical data signals to a corresponding electrical data signal. The WDM may then convert the corresponding electrical data signal to a second optical data signal, wherein the second optical data signal may be an optical data signal with signal characteristics commensurate for use with a SONET/SDH, IP, or ATM client-layer optical network.

As mentioned above, the WDM may also be a circulator, or function as a circulator. The circulator in the WDM may be an optical circulator comprised of a fiber-optic component that can be used to separate upstream signals and downstream signals. The optical circulator may be a three-port or four-port device in which an optical data signal entering one port will exit the next port. The optical circulator may be in the shape of a square, with a first port on the left side of the square, a second port on the right side of the square, and a third port on the bottom side of the square. A first optical data signal (e.g., a downstream signal) entering the first port may exit the second port. A second optical data signal (e.g., an upstream signal) entering the third port may exit the first port.

An upstream signal, as referred to herein, may be a flow one or more packets of light, oscillating with a predetermined wavelength, along one or more optical fibers in a direction toward the OCML headend from a field hub or outside plant. A downstream signal, as referred to herein, may be a flow of one or more packets of light, oscillating with a predetermined wavelength, along one or more optical fibers in a direction away from the OCML headend and toward the field hub or outside plant. The one or more packets of light may correspond to one or more bits of data. Both downstream and upstream signals propagate along the same optical fiber, but in opposite directions. In some embodiments, the downstream and upstream signals may propagate along the same fiber simultaneously using one or more wavelength multiplexing techniques as explained below. This bidirectional simultaneous communication between the OCML headend and the outside plant may be referred to as a full duplex connection. Field hub and outside plant may be used interchangeably.

In some embodiments, the OCML headend may also comprise a booster optical amplifier, that amplifies downstream signals based on the length of a fiber between the OCML headend and the outside plant. The booster optical amplifier may be an Erbium Doped Fiber Amplifier (EDFA). The core of the EDFA may be an erbium-doped optical fiber, which may be a single-mode fiber. The fiber may be pumped, by a laser, with one or more packets of light in a forward or backward direction (co-directional and counter-directional pumping). The one or more packets of light pumped into the fiber, may have a wavelength of 980 nm. In some embodiments the wavelength may be 1480 nm. As the one or more packets of light are pumped into the fiber erbium ions (Er³⁺) are excited and transition into a state where the ions can amplify the one or more packets of light with a wavelength within the 1.55 micrometers range. The EDFA may also comprise two or more optical isolators. The isolators may provent light pumped into the fiber that leaves the EDFA from returning to the EDFA or from damaging any other electrical components connected to the EDFA. In some embodiments, the EDFA may comprise fiber couplers and photodetectors to monitor optical power levels. In other embodiments, the EDFA may further comprise pump laser diodes with control electronics and gain flattening filters. The EDFA may have the effect of amplifying each of the one or more optical data signals, while they are combined in a multi-wavelength optical data signal, without introducing any effects of gain narrowing. In particular, the EDFA may simultaneously amplify the one or more optical data signals, each of which have a different wavelength, within a gain region of the EDFA. A gain of the booster optical amplifier may be based at least in part on the length of the fiber. In some embodiments, the length of the fiber may be between 5 and 60 kilometers.

The OCML headend may also comprise an optical pre-amplifier that may amplify upstream signals. The optical pre-amplifier may also be an EDFA. The optical pre-amplifier may amplify upstream signals based on the length of the fiber between the outside plant and the OCML headend to account for any loses in the strength of the upstream signals propagating along the fiber. The gain of the optical pre-amplifier may be based at least in part on a required signal strength of the upstream signals at an input to the DWDM passive circuit, in order for the DWDM to demultiplex the upstream signals. The optical pre-amplifier may have the effect of amplifying a multi-wavelength optical data signal, so that the one or more optical data signals in the multi-wavelength optical data signal, each of which have different respective wavelengths, have a certain received power level at a DWDM passive circuit upstream input port.

The optical signal to noise ratio (OSNR) of the EDFA may be based at least in part on an input power to the EDFA, a noise figure. In some embodiments the OSNR of the EDFA may be determined by the expression OSNR=58 dB−NF−P_in, where NF is the noise floor, P_inis the input power to the EDFA. 58 dB is constant that is based on Planck's constant, the speed of light, the bandwidth of the EDFA, and the wavelength of the one or more packets of light. In some embodiments, the OSNR of the EDFAs disclosed herein may be as high as 40 dB, for one or more packets of light that are transmitted downstream from OCML headend. The OSNR of the transceivers disclosed herein may be as low as 23 dB, and there may be a plurality of bit error rate (BER) values associated with this 23 dB OSNR. The BER may be determined based at least in part on the energy detected per bit, noise power spectral density, and a complementary error function. More specifically the BER may be

$\left(\frac{dv}{d\omega }\right)$
wherein E_bis the energy detected per bit, No is the noise power spectral density, and erfc is the complementary error function. For instance, the transceivers disclosed herein may be able to achieve a BER of 10⁻¹²when the common logarithm ratio of received power to 1 milliwatt (mW) is −23 dBm. For example, a transceiver in the OCML headend may receive an upstream flow or one or more packets of light, from a transceiver in the field hub or outside plant, that has a common logarithm ratio of received power per mW of −23 dBm. The BER may be greater for common logarithm ratios of received power per mW, meaning that the BER may decrease with the higher common logarithm ratios of received power per mW. The transceivers may be configured to have greater OSNRs, and therefore lower BERs for the same value of a common logarithm ratio of received power per mW. For example, a first transceiver configured to have an OSNR of 24 dB with a common logarithm ratio of received power per mW of −28 dBm may have an approximate BER of 10⁻⁵and a second transceiver configured to have an OSNR of 26 dB with a common logarithm ratio of received power per mW of −28 dBm may have an approximate BER of 10′. Thus, transceivers configured to have a higher OSNR results in the transceiver having a lower BER for the same common logarithm ratio of received power per mW.

The OCML headend may also comprise an optical switch that may connect a WDM to a primary optical fiber connecting the OCML passive circuit to the outside plant. The optical switch may also connect the WDM to a secondary optical fiber connecting the OCML passive circuit to the outside plant. The optical switch may be in a first position that connects the WDM to the primary optical fiber, and may be in a second position that connects the WDM to the secondary optical fiber. The optical switch may be in the second position when the primary optical fiber is disconnected or unresponsive.

Because the OCML headend, field hub or outside plant, and fiber connecting the OCML headend and field hub or outside plant mainly comprise passive optical components, in comparison to other optical ring networks that primarily have active components, one or more devices may be needed to control for dispersion of light as it goes through different optical components. In particular, as packets of light traverse the different optical components in the OCML headend (e.g., WDMs and/or optical amplifiers including booster amplifiers or pre-optical amplifiers), an optical data signal being carried by the packets of light may begin to experience temporal broadening which is a form of optical data signal distortion. Because the OCML systems disclosed herein transmit high data rate optical data signals, about 10 Gbps, there may be some strong dispersive temporal broadening effects introduced by one or more of the optical components in the OCML headend. The optical data signals disclosed herein may carry digital symbols, which are a series of binary digits (1 or 0), and each binary digit may be represented by a pulse of light (one or more packets of light) of a certain amplitude, that lasts a certain period. For example, an optical data signal may be carrying a plurality of digital symbols, wherein a pulse of light that has a certain amplitude and certain pulse width (certain period) represents each binary digit in a digital symbol of the plurality of digital symbols. The pulse widths of each of the pulses of light may begin to broaden as each of the pulses of light traverses different optical components. As a result, the symbol may begin to broaden. Consequently, as each of the symbols begins to broaden in time, and may become indistinguishable from an adjacent symbol. This may be referred to as intersymbol interference (ISI), and can make it difficult for a fiber-optic sensor or photodetector receiving the optical data signal to distinguish adjacent symbols from one another. In order to compensate for this phenomenon, a dispersion compensation module (DCM) may be inserted between one or more optical components in the OCML headend. For example, a DCM may be receive an optical data signal output from a WDM to compensate for any potential ISI that may be introduced as a result of different optical data signals, carried over pulses of light, that have been combined, multiplexed, or circulated in the WDM. The DCM can also compensate for dispersion characteristics of the fiber between the OCML headend and the field hub or outside plant. In particular, the fiber may comprise certain optical elements or material impurities that can be compensated for in the DCM, wherein the DCM comprises long pieces of dispersion-shifted fibers or chirped fiber Bragg gratings. The dispersion-shifted fibers or chirped fiber Bragg gratings can reduce ISI that is introduced by the fiber. In some embodiments, the OCML headend may comprise one or more DCMs to compensate for ISI that may be introduced by one or more optical components in the OCML headend or fiber that is either upstream or downstream from the one or more DCMs. For example, in one embodiment, a first DCM may be positioned downstream from a first WDM and a second DCM may be positioned upstream from a second WDM. This embodiment is illustrated inFIG. 1, and further explained below.

It should be noted that the DCMs may cause negative dispersion for shorter lengths of fiber (e.g., lengths of fiber less than 5 kilometers). Negative dispersion may occur when a flow of one or more packets of light, forming a wave, propagate along a distance of the fiber with a negative rate of change. The wave propagates along the fiber, and the wave has an electric field associated with it that is normal to the direction of propagation of the wave, and a magnetic field associated with it that is normal to the electric field and the direction of propagation of the wave. The wave propagates along the fiber with an angular frequency, ω, which may be a function of a propagation constant β. The electric and magnetic fields may both oscillate in accordance with sinusoidal function e^i(βz-ωt), wherein z is a distance that the wave has traveled in the fiber, and t is the time elapsed after the wave has been transmitted by the DCM. That is the electric and magnetic field may oscillate in accordance with a sinusoidal function equal to cos(βz-ωt)+isin(βz-ωt), wherein the oscillation of the wave is based at least in part on the propagation constant, and angular frequency, and the amount of time that has elapsed since the wave has been transmitted by the DCM. The angular frequency may be reciprocal of the amount of time that the electric and magnetic fields oscillate an entire cycle or period. The propagation constant may be a complex quantity, wherein the real part of the propagation constant is a measure of a change in the attenuation of the wave as it propagates along the fiber. The real part of the propagation constant may be referred to as an attenuation constant. The imaginary part of the propagation constant is a measure of a change in the phase of the wave as it propagates along the fiber. Because the angular frequency may be based at least in part on the propagation constant, the angular frequency of the wave may change as the attenuation and phase of the wave change. Accordingly, the velocity of the wave may change as it propagates along the fiber and may begin to experience dispersion. The velocity of the wave may be the rate at which the angular frequency changes as the propagation constant changes while the wave propagates along the fiber. That is the velocity of the wave may be expressed as

$v=\frac{d\omega }{d\beta }.$
The wavelength of the wave may be expressed as

$\lambda =2\pi \frac{c}{\omega },$
wherein c is the speed of light. The dispersion of the wave may be based at least in part on the speed of light, wavelength of the wave, velocity of the wave, and the rate of change of the velocity of the wave with respect to the angular frequency. The dispersion of the wave may be expressed as

$D=\frac{2\pi \mathrm{<figure-callout\; label="c\; v"\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">c</figure-callout>}}{v^{}}\frac{dv}{d\omega }.$
D is a dispersion parameter of the wave and is based on the speed of light (c), the velocity of the wave (v), the wavelength of the wave (λ), and the rate of change or first derivative of the velocity of the wave with respect to the angular frequency of the wave

$\left(\frac{dv}{d\omega }\right).$
The dispersion parameter indicates whether the wave experiences positive dispersion (temporal broadening) or negative dispersion (temporal contraction) as the wave propagates along the fiber. Negative dispersion may occur when the rate of change or derivative of the velocity of the wave, with respect to the angular frequency is negative. When

$\frac{1}{2}\mathrm{erfc}\left(\sqrt{\frac{E_b}{N_0}}\right),$
is negative, the wave is said to be experiencing negative dispersion. Thus when the rate of change of the velocity of the wave with respect to the angular frequency is negative, the wave may experience temporal contraction. Accordingly, transceivers in the transponders of the DWDM of the field hub or outside plant must be capable of detecting waves subject to negative dispersion. Negative dispersion is the opposite of positive dispersion in that ISI may not occur when a wave is detected at the transceivers in the transponders of the DWDM of the field hub or outside plant. However, temporal contraction of the wave may make it difficult for a fiber-optic sensor or photodetector to detect an optical data signal carrying digital symbols, because the digital symbols in the optical data signal may begin to overlap with one another. This may happen because each of the digital symbols are a series of binary digits, and the binary digits are represented by a pulse of light (one or more packets of light in the wave), and as the wave begins to experience negative dispersion, each of the binary digits may begin to overlap with one another. The transceivers disclosed herein are equipped with fiber-optic sensors or photodetectors that are capable of correctly detecting the one or more packets of light in the wave, when the wave is subject to positive and/or negative dispersion. The DCMs disclosed herein may transmit a signal a distance of 30 kilometers.

The OCML headend may also comprise a non-optical switch that switches due to a loss of light or on demand.

The OCML headend may also comprise wavelength-monitoring ports that connect to the primary and secondary optical fibers to monitor the wavelength of upstream signals comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, and/or XGPON/10GEPON signals and/or to monitor the wavelength of downstream signals comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON signals.

Certain embodiments of the disclosure are directed to an OCML, systems, and methods. Embodiments of the disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like numbers refer to like elements throughout.

It should be noted that the OCML headend may also be referred to as a terminal or Master Terminal Center (MTC). In some embodiments, the OCML headend may be collocated within the MTC. In other embodiments, the OCML headend may be located at a secondary transport center (STC) that may be connected to the MTC via a network. In some embodiments, an outside plant may also be referred to as a field hub or remote physical device (RPD). In some embodiments, the outside plant may be collocated with the RPD. In other embodiments, the outside plant and RPD may not be collocated and connected via a 10 Gigabit transceiver. The outside plant may comprise one or more passive optical network devices.

FIG. 1 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 1,headend101 is a smart integrated OCML headend, which is a circuit, comprising one or more EDFAs (e.g.,Optical amplifiers102 and104), a DWDM (e.g., DWDM106), one or more WDMs (e.g.,WDM108 and110), one or more DCMs (e.g.,DCM112 and114), and anoptical switch116 to feed a primary optical fiber (e.g., Primary Fiber176) or secondary (backup) optical fiber (e.g., Secondary Fiber174). The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's MTC facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

In one aspect,headend101 may comprise twenty 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS190) and twenty 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP188). 20×10GNRZ, 100 GbE, 200 GbE, and/or 400 GbE190 may transmit downstream data over twenty 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10GNRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may receive upstream data over 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths.Headend101 may comprise twoPON124 connectors, one of which may be a GPON connector (e.g., GPON184) and one of which may be an XGPON/10GEPON connector (e.g., XGPON/10GEPON182).Headend101 may also comprise two wavelength-monitoring ports (e.g., wavelength-monitoring ports126), a primary optical fiber (e.g., primary optical fiber176) and a secondary optical fiber (e.g., secondary optical fiber174) that transmit and receive a plurality of multi-wavelength coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON optical signals. Primaryoptical fiber176 and secondaryoptical fiber174 may transmit a first plurality of multi-wavelength 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON optical signals fromheadend101 to a outside plant (not illustrated inFIG. 1), and may receive a second plurality of multi-wavelength 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON optical signals from the outside plant.

In some embodiments, 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may comprise connectors belonging to the laser shock hardening (LSH) family of connectors designed to transmit and receive optical data signals betweenDWDM106, and one or more cable company servers (not shown). In other embodiments, 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may also comprise E2000 connectors, and may utilize a 1.25 millimeter (mm) ferrule. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may be installed with a snap-in and push-pull latching mechanism, and may include a spring-loaded shutter which protects the ferrule from dust and scratches. The shutter closes automatically once the connector is disengaged, locking out impurities, which could later result in network failure, and locking in possibly damaging lasers. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may operate in a single mode or a multimode.

In single mode, 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 only one mode of light may be allowed to propagate. Because of this, the number of light reflections created as the light passes through the core ofsingle mode 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 decreases, thereby lowering attenuation and creating the ability for the optical data signal to travel further. Single mode may be for use in long distance, higher bandwidth connections between one or more cable company servers andDWDM106.

In multimode, 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188, may have a large diameter core that allows multiple modes of light to propagate. Because of this, the number of light reflections created as the light passes through the core increase, creating the ability for more data to pass through at a given time. Multimode 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188, may generate high dispersion and a attenuation rate, which may reduce the quality of an optical data signal transmitted over longer distances. Therefore multimode may be used to transmit optical data signals over shorter distances.

In one aspect,headend101 can transmit and receive up to twenty bi-directional 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, but the actual number of optical data signals may depend on operational needs. That is,headend101 can transport more or less than twenty 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream optical signals, or more or less than twenty 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream optical data signals, based on the needs of customers' networks (e.g.,Remote PHY Network216,Enterprise Network218, Millimeter Wave Network214). These customer networks may be connected toheadend101 through an optical ring network (e.g., metro access optical ring network206).

The operation ofheadend101 may be described by way of the processing of downstream optical data signals transmitted fromheadend101 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM106 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS98) comprising the twenty corresponding second optical data signals onto a fiber. More specifically,DWDM106 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength downstream optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS198, may be input to a WDM (e.g. WDM108).WDM108 may be a three port wave division multiplexer (WDM), or a three port circulator, that receives 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS198 onport194 and outputs 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS198 on port186 as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172 may be substantially the same as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS198 becauseWDM108 may function as a circulator when 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172 is input onport194.

10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172 may be input into a DCM (e.g., DCM112) to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172 may experience after being amplified by an EDFA and multiplexed by a WDM, with other optical data signals, that are downstream from the DCM. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend101 over afiber connecting headend101 to a field hub or outside plant. In some embodiments,DCM112 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments,DCM112 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically,DCM112 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.

DCM112 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS172 and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS170 to an EDFA (e.g., booster optical amplifier102). A gain of the booster optical amplifier (e.g., booster optical amplifier102) may be based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, the gain of boosteroptical amplifier102 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain of boosteroptical amplifier102 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber176 and/or the length of secondary fiber174). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS170 may be amplified by boosteroptical amplifier102, and boosteroptical amplifier102 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS178 to port164 ofWDM110.

WDM110 may be a WDM that may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS178 with one or more PON signals (e.g., XGPON/10GEPON182 and GPON184). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS178 may be a multi-wavelength optical data signal, wherein the wavelengths comprise the same wavelengths as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS198. In some embodiments, the wavelengths of the multi-wavelength optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS178 may be within the conventional c band of wavelengths, which may include wavelengths within the 1520 nm-1565 nm range. XGPON/10GEPON182 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1582 nm range. GPON184 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm. The XGPON/10GEPON optical signal may be input toWDM110 onport162 and the GPON signal may be input toWDM110 onport160.WDM110 outputs an egress optical data signal fromport156, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, signals.WDM110 may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS178, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM106 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal152) may be output onport158 ofWDM110 andoptical switch116 may switch egress optical data signal152 out ofconnector118 or connector150. In some embodiments,connector118 may be a primary connector and connector150 may be a secondary connector or a backup connector.Wavelength monitoring connector146 may connectconnector118 to a first port of wavelength-monitoring ports126, and wavelength monitoring connector148 may connect connector150 to a second port of wavelength-monitoring ports126. Wavelength-monitoring ports126 may monitor the wavelengths in egress optical data signal152 viaconnector146 or connector148 depending on the position ofswitch116. Egress optical data signal152 may exitheadend101 either viaconnector144 connected toprimary fiber176 or viaconnector142 connected tosecondary fiber174 depending on the position ofswitch116. Egress optical data signal152 may be transmitted onprimary fiber176 to a first connector in the field hub or outside plant, or may be transmitted onsecondary fiber174 to a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

The operation ofheadend101 may be described by way of the processing of upstream optical data signals received atheadend101 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, XGPON/10GEPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber176 orsecondary fiber174 depending on the position ofswitch116. Because the multi-wavelength ingress optical data signal is routed to port158 ofWDM110, and is altered negligibly betweenconnector144 andport158 orconnector142 andport158, depending on the position ofswitch116, the multi-wavelength ingress optical data signal may be substantially the same as ingress optical data signal154. The multi-wavelength ingress optical data signal may traverseconnector118 and switch116, before enteringWDM110 viaport158 ifswitch116 is connected toconnector118. The multi-wavelength ingress optical data signal may traverse connector150switch116, before enteringWDM110 viaport158 ifswitch116 is connected to connector150.WDM110 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, XGPON/10GEPON optical data signals, and/or GPON optical data signals from ingress optical data signal154.WDM110 may transmit the one or more XGPON/10GEPON optical data signals along XGPON/10GEPON182 to one ofPON connectors124 viaport162.WDM110 may transmit the one or more GPON optical data signals along GPON184 to one ofPON connectors124 viaport160.WDM110 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP180) out ofport156 toDCM114.

In some embodiments,DCM114 may be configured to balance positive and/or negative dispersion that may be introduced to a SONET/SDH egress optical data signal that may exitheadend101 from 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188. The SONET/SDH egress optical data signal may be an upstream signal from a field hub or outside plant destined for a MTC. For example, a customer premise may be connected to the field hub or outside plant and may send one or more packets via a SONET/SDH network to the field hub or outside plant which may in turn transmit the one or more packets using 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals toheadend101. The one or more packets may be destined for a company web server connected to the MTC via a backbone network. Becauseheadend101 may be collocated in a STC that is connected to the MTC via an optical ring network, wherein the connection between the STC and MTC is an SONET/SDH optical network connection,DCM114 may be configured to compensate for positive and/or negative dispersion on the SONET/SDH optical network connection. That isDCM114 may be configured to reduce temporal broadening of the SONET/SDH ingress optical data signal or temporal contraction of the SONET/SDH ingress optical data signal.DCM114 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP180 and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP166 to an input of EDFA (e.g., optical pre-amplifier104).

A gain ofoptical pre-amplifier104 may be based at least in part on a distance that the SONET/SDH egress optical data signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment on the SONET/SDH optical network connection. For instance, the gain ofoptical pre-amplifier104 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain ofoptical pre-amplifier104 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length of the fiber of the SONET/SDH optical network connection). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP166 may be amplified byoptical pre-amplifier104, andoptical pre-amplifier104 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 toWDM108.

The wavelength of 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 may be within the conventional c band of wavelengths, which may include wavelengths within the 1520 nm-1565 nm range. The one or more XGPON/10GEPON optical data signals may have a wavelength within the 1571 nm-1582 nm range, and the one or more GPON optical data signals may have a wavelength of 1490 nm.

WDM108 may receive 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 onport192, and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 onport194 as a multi-wavelength upstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP196). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP196 is substantially the same 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 becauseWDM108 may function as a circulator when 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP168 is input toport192. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP196 may be received byDWDM106, and DWDM may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals from 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP196. Because 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP196 is a dispersion compensated amplified version of the multi-wavelength ingress optical data signal,DWDM106 may demultiplex the one or more optical data signals into individual optical data signals in accordance with the individual wavelengths of any 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals in the multi-wavelength ingress optical data signal. More specifically, 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP196 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM106 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×coherent 100 GbE, 200 GbE, and/or 400GbE UP188. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may convert a received corresponding coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 2A depicts a network architecture, in accordance with the disclosure. The network architecture may comprise routers (forexample router287 and router285) that may be capable of routing one or more packets from a backbone network (not illustrated) to an OCML terminal (for example, OCML terminal207).

Router287 may be a router that aggregates one or more first ingress packets received from the backbone network to a transport chassis (for example transport chassis290).Router287 may also receive one or more first egress packets fromtransport chassis290 and route the one or more first egress packets to the backbone network. The backbone network may be a network connecting one or more service provider networks across a large geographic area such as a content (for example North America). The one or more first ingress packets and the one or more first egress packets may be transmitted betweenrouter287 andtransport chassis290 via a plurality of 100 GbE, 200 GbE, and/or 400 GbE links. The plurality of 100 GbE, 200 GbE, and/or 400 GbE links may be SONET/SDH optical data signal links.

Transport chassis290 may be a physical platform that accommodates a plurality of optical devices including a coherent transceiver.Transport chassis290 may create a coherent optical data signal, which may be, for example, an optical data signal comprising coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.Transport chassis290 may send coherent optical data signals toOCML terminal207, andtransport chassis290 may receive coherent optical data signals fromOCML terminal207.

Switch291 may be an optical switch that receives one or more second ingress packets from router285 and may transmit one or more second ingress frames, corresponding to the one or more second ingress packets, out of a port inswitch291 toOCML terminal207. The one or more second ingress packets may be received via a plurality of 100 GbE, 200 GbE, and/or 400 GbE links. And the one or more second ingress frames may be switched out of the port inswitch291 to OCML terminal207 as an optical data signal via a coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal switch.Switch291 may receive one or more second egress frames fromOCML terminal207, create one or more second egress packets, and transmit the one or more egress packets to router285.

OCML terminal207 may connect a cable company to the Internet through the backbone network.OCML terminal207,Primary Optical Fiber211,Secondary Optical Fiber213, andMDM208 form a network that may be referred to as the Metro Access Optical Ring Network (for example Metro Access Optical Ring Network206).Millimeter Wave Network214 may be connected toMDM208 via connection254. Multi-dwelling unit (MDU)216 may be connected toMDM208 viaconnection256 andtransport chassis207.Enterprise Network218 may be connected toMDM208 viaconnection258.Devices299 are connected toMDM208 viaconnections225 . . .227,aggregation device223, andconnection251. An illustrative aggregation device is illustrated inFIG. 21.

Millimeter Wave Network214 may comprise one or more cellular or Wi-Fi masts with one or more modems (for example Modem212) that provide mobile devices (for example devices215) with access to content hosted by the one or more servers at a MTC Master Terminal Facility (not illustrated).

MDU216 may comprise one a remote physical (PHY) node (for example Remote PHY Node207) that may comprise an optical communications interface that connects toconnection256 and a cable interface that connects to one or more cable devices (for example devices217) via cable. The one or more cable devices may be devices connecting cable set-top boxes in one or more residential, commercial, or industrial buildings to a tap atdevices217.Devices217 is connected toconnection256 viatransport chassis207.

Enterprise Network218 may comprise one or more offices requiring high-speed access to the Internet via Backbone Network202 for example.Enterprise Network218 may connect to the Internet viaconnection258.

Device265 may be a cable device that is connected toMDM208 viaconnection245. A l×n splitter293 may be an optical splitter or a beam splitter. 1×n splitter293 may comprise one or more quartz substrates of an integrated waveguide optical power distribution device. 1×n splitter293 may be a passive optical network device. It may be an optical fiber tandem device comprising one or more input terminals and one or more output terminals. 1×n splitter239 may be Fused Biconical Taper (FBT) splitter or Planar Lightwave Circuit (PLC) splitter. 1×n splitter293 may be a balanced splitter wherein 1×n splitter293 comprises two input fibers and one or more output fibers over which the ingress optical data signal may be spread proportionally. In some embodiments, the ingress optical data signal may not be spread proportionally across the output fibers ofoptical splitter1593. In some embodiments,optical splitter1593 may comprise two input fibers and 2 output fibers. A first input fiber ofoptical splitter1593 may be connected toprimary fiber1550 and a second input fiber ofoptical splitter1593 may be connected tosecondary fiber1551 . . . 1×n splitter293 may be connected toMDM208 viaconnection252. 1×n splitter297 may be a . . . 1×n splitter297 may be connected toMDM208 via optical link terminal (OLT)295 andconnection253. Devices215,device217,devices299,device265, lxn293, lxn297, and the one or more devices inenterprise network218 may be connected to the backbone network via Metro AccessOptical Ring Network206.

FIG. 2B depicts an network architecture, in accordance with the disclosure. The network architecture may comprise a MTC Master Terminal Facility (for example MTC Master Terminal Facility201) that may connect a cable company to the Internet through a backbone network (for example Backbone Network202). MTC Master Terminal Facility201 may include one or more servers hosting content that may be consumed by customer devices connected to the one or more servers via one or more networks. For example, the one or more networks may include cellular or millimeter wave networks (for example Millimeter Wave Network214), remote physical networks (for example Remote PHY Network216), enterprise networks (for example Enterprise Network218), and one or more passive optical networks (PON) (for example PON222 and PON242). MTC Master Terminal Facility201 may be connected to these one or more networks via one or more optical fibers (for examplePrimary Optical Fiber211 and Secondary Optical Fiber213). MTC Master Terminal Facility201 may connect to the one or more optical fibers via an OCML terminal (for example, OCML terminal207), and the one or more networks may connect to the one or more optical fibers via a MDM (for example MDM208) comprising multiplexer-demultiplexer (for example DMux288), and PON port (for example PON298).OCML207,Primary Optical Fiber211,Secondary Optical Fiber213, andMDM208 form a network that may be referred to as the Metro Access Optical Ring Network (for example Metro Access Optical Ring Network206). DMux288 may multiplex optical data signals received from the one or more networks and transmit the multiplexed optical data signals to OCML207. Conversely DMux288 may demultiplex optical data signals received fromOCML207 and transmit the demultiplexed optical data signals to the one or more networks.Millimeter Wave Network214 may be connected to DMux288 via connection254.Remote PHY Network216 may be connected to DMux288 viaconnection256.Enterprise Network218 may be connected to DMux288 viaconnection258. PON222 may be connected to DMux288 viaconnection251. PON242 however may be connected to PON298 viaconnection253.

Millimeter Wave Network214 may comprise one or more cellular or Wi-Fi masts with one or more modems (for example Modem212) that provide mobile devices (for example devices215) with access to content hosted by the one or more servers at MTC Master Terminal Facility201.

Remote PHY Network216 may comprise one a remote physical (PHY) node (for example Remote PHY Node207) that may comprise an optical communications interface that connects toconnection256 and a cable interface that connects to one or more cable devices (for example devices217) via cables226-cable236. The one or more cable devices may be devices connecting cable set-top boxes in one or more residential, commercial, or industrial buildings to a tap atdevices217.

Enterprise Network218 may comprise one or more offices requiring high-speed access to the Internet via Backbone Network202 for example.Enterprise Network218 may connect to the Internet viaconnection258.

PON222 may comprise one or more PON devices (for example devices299) that require access to MTC Master Terminal Facility201 or the Internet via for Backbone Network202 for example.Devices299 may be connected to a splitter (for example Splitter223) via connections225-connection227.Splitter223 is an optical splitter that may combine one or more optical data signals from each ofdevices299 and transmit them to Strand PON optical line terminal (OLT)210 viaconnection252.Splitter223 may also separate one or more optical data signals received from Strand PON OLT210 viaconnection252 into one or more optical data signals for each ofdevices299. Strand PON OLT210 may be an OLT that connects optical network units (ONUs) at a customer premises to DMux288. Because one or more optical data signals can be transmitted as a multiplexed signal on a single strand of fiber, Strand PON OLT210 may be connected to other PONs (not shown), in addition to PON222, and may combine optical data signals received from the PONs and transmit the combined optical data signals to DMux288. Strand PON OLT210 may separate optical data signals received from DMux288 into corresponding optical data signals each of which is for transmission to a corresponding PON.

PON242 may comprise one or more PON devices (for example devices249) that require access to MTC Master Terminal Facility201 or the Internet via for Backbone Network202 for example. Devices249 may be connected to a splitter (for example Splitter243) via connections224-connection247. Splitter243 is an optical splitter that may combine one or more optical data signals from each of devices249 and transmit them to PON298 viaconnection253. Splitter243 may also separate one or more optical data signals received from PON298 viaconnection253 into one or more optical data signals for each of devices249.OCML207 inFIGS. 2A and 2B may be implemented asheadend101,headend330,headend530,headend630,headend1001,headend1086,headend1102,headend1201,headend1301,headend1401,headend1501,headend1601, orheadend1701.

FIG. 3 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.FIG. 3 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 3,headend330 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM307), a WDM (e.g., WDM305), a GPON port (e.g., GPON PORT301), an XGPON/10GEPON port (e.g., XGPON/10GEPON PORT303), and anoptical switch308 to feed a primary optical fiber (e.g., Primary Fiber309) or secondary (backup) optical fiber (e.g., Secondary Fiber311).DWDM307 may be similar in functionality toDWDM106 and WDM305 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or/XGPON/10GEPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a outside plant (e.g., Outside plant350). The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a outside plant or field hub which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

In one aspect,headend330 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS304) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP306). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend330 may be described by way of the processing of downstream optical data signals transmitted fromheadend330 to a outside plant (e.g., Outside plant350), and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM307 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g.,336) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal336 may be a 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM307 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal336, may be input to a WDM (e.g. WDM305). WDM305 may be a four port wave division multiplexer (WDM), or a four port circulator, that receives multi-wavelength downstream optical data signal336 onport321. WDM305 may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON334), onport302, a GPON signal, carried on a second fiber (e.g., GPON332), onport322, and may multiplex multi-wavelength downstream optical data signal336 with the XGPON/10GEPON and GPON signal. XGPON/10GEPON334 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm and 1260 nm-1280 nm range.GPON332 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm and 1310 nm. WDM305 outputs an egress optical data signal fromport324, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals. WDM305 may multiplex multi-wavelength downstream optical data signal336, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM307 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal338) may be output onport324 of WDM305 andoptical switch308 may switch egress optical data signal338 ontoprimary fiber309 orsecondary fiber311 depending on the position ofswitch308. Egress optical data signal338 may be transmitted onprimary fiber309 to a first connector atoutside plant350, or may be transmitted onsecondary fiber311 to a second connector atoutside plant350.Outside plant350 may include a MDM with the first connector and the second connector.

The operation ofoutside plant350 may be described by way of the processing of a downstream optical data signal received fromheadend330. Egress optical data signal338 may be received on the first or second connector atoutside plant350 based on a position of optical switch380, as ingress optical data signal356. That is ingress optical data signal356 may be similar to egress optical data signal338. Ingress optical data signal356 may be received byWDM313 viaport372.WDM313 may demultiplex ingress optical data signal356 into a multi-wavelength downstream optical data signal359, an XGPON/10GEPON optical data signal that may be output onport392 onto a first fiber (e.g., XGPON/10GEPON354), and/or a GPON optical data signal output onport382 onto a second fiber (e.g., GPON352). The XGPON/10GEPON optical data signal may be received on XGPON/10GEPON port353 and the GPON optical data signal may be received onGPON port351.

The multi-wavelength downstream optical data signal359 may be output on port362 and received byDWDM315 which may be an array waveguide gratings (AWG) or TFF. The multi-wavelength downstream optical data signal359 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM315 may demultiplex the multi-wavelength downstream optical data signal359 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength downstream optical data signal359 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM315 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS312. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS312 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. In some embodiments,DWDM315 may output one or more coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., RPD DS327) to a remote physical (PHY) device (RPD) (e.g., RPD317). RPD317 may be similar toRemote PHY Node207 in functionality. RPD317 may convert the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into an electrical signal that may be transmitted over one or more coaxial cables. RPD317 may also convert one or more electrical signals into one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal for transmission to a transponder (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP314).

The operation ofoutside plant350 may be further described by way of the processing of an upstream optical data signal transmitted toheadend330. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP314 may receive a SONET/SDH optical data signal from one or more devices providing cable to customers or subscribers to a cable's services. For example, the one or more devices may be any ofdevices217, andRPD327 may be connected todevices217 via cable226 . . . cable236. Cable226 . . . cable236 may be coaxial cables. Each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP314 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP314 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM315 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g.,358) comprising the twenty corresponding second optical data signals onto a fiber. In some embodiments, RPD317 may transmit one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., RPD DS331) to one or more of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP314.RPD DS331 may be 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals that generated by RPD317 in response to RPD317 receiving electrical signals on coaxial cables connecting a remote physical (PHY) network (e.g., remote PHY network216) toDWDM315. The multi-wavelength downstream optical data signal358 may be a coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM315 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal358, may be input to a WDM (e.g. WDM313).WDM313 may be a four port wave division multiplexer (WDM), or a four port circulator, that receives multi-wavelength downstream optical data signal358 on port362.WDM313 may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON354), onport392, a GPON signal, carried on a second fiber (e.g., GPON352), onport382, and may multiplex multi-wavelength downstream optical data signal358 with the XGPON/10GEPON and GPON signal. XGPON/10GEPON354 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm and 1260 nm-1280 nm range.GPON352 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm or 1310 nm.WDM313 outputs an egress optical data signal fromport372, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.WDM313 may multiplex multi-wavelength downstream optical data signal358, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM307 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal357) may be output onport372 ofWDM313 and optical switch380 may switch egress optical data signal357 ontoprimary fiber309 orsecondary fiber311 depending on the position of switch380. Egress optical data signal357 may be transmitted onprimary fiber309 to a first connector atheadend330, or may be transmitted onsecondary fiber311 to a second connector atheadend330.

The operation ofheadend330 may be further described by way of the processing of an upstream optical data signal received fromoutside plant350. Egress optical data signal357 may be received on the first or second connector atheadend330 based on a position ofoptical switch308, as ingress optical data signal339. That is ingress optical data signal339 may be similar to egress optical data signal357. Ingress optical data signal339 may be received by WDM305 viaport324. WDM305 may demultiplex ingress optical data signal339 into a mutli-wavelength upstream optical data signal337, an XGPON/10GEPON optical data signal that may be output onport302 onto a first fiber (e.g., XGPON/10GEPON334), and/or a GPON optical data signal output onport322 onto a second fiber (e.g., GPON332). The XGPON/10GEPON optical data signal may be received on XGPON/10GEPON port303 and the GPON optical data signal may be received onGPON port301.

The multi-wavelength upstream optical data signal339 may be output, as multi-wavelength upstream optical data signal337, onport321 and received byDWDM307. The multi-wavelength upstream optical data signal337 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM307 may demultiplex the multi-wavelength upstream optical data signal337 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength upstream optical data signal337 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM307 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 4 shows an access link loss budget of a Dense Wave Division Multiplexing (DWDM) passive circuit, in accordance with the disclosure. Link loss budget400 illustrates the link loss budget in decibels (dB) associated with a physical optical link connecting an OCML transceiver to a outside plant transceiver. The OCML headend and outside plant transceiver may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE transceivers that may not contribute to the loss budget. That is there may be no power lost when the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE transceivers transmit a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. Thus, Txcvr Pwr/WL401 may be equal to 0.0 when a transceiver at an OCML headend transmits a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal to a outside plant transceiver, and when the transceiver at the outside plant transmits a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal to the OCML terminal. The transceiver in the OCML headend may be similar to a transceiver included in the transponders disclosed herein (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 or 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188 inheadend101 or 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS304 or 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP306 in OCML headend301). The transceiver in the outside plant may be similar to a transceiver included in the transponders disclosed herein (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS312 or 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP314).

In some embodiments, the fiber connecting the transceiver at the OCML headend to the outside plant, may be 5 kilometers (km). Thusfiber402 may be 5 km in length and when a transceiver in the OCML headend transmits an optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal) to a transceiver in the outside plant alongfiber402,fiber402 may cause the optical data signal to experience a 1.25 dB loss. Similarly, when the transceiver in the outside plant transmits an optical data signal to the OCML headend alongfiber402,fiber402 may cause the optical data signal to experience a 11.25 dB loss.

In some embodiments, a multiplexer in a DWDM (e.g.,DWDM106 or DWDM307) in an OCML headend may contribute to the loss budget. This may be based at least in part on the multiplexing process applied to multiple input optical data signals received from multiple transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190 or 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS304). The multiplexing process may result in the multiplexed optical data signal having less power than the multiple input optical data signals. The OCML headend in some embodiments, may also be referred to as the headend, and thusheadend DWDM mux403 is the loss budget associated with the multiplexing of multiple input optical data signals. The loss budget forheadend DWDM mux403 may be 5.8 dB. Similarly a demultiplexer in a DWDM in a outside plant may contribute to the loss budget. This may be based at least in part on the demultiplexing process applied to a multiplexed optical data signal received from the DWDM in the headend. The demultiplexing process may result in each of the demultiplexed optical data signals, included in the received multiplexed optical data signal, having less power than the received multiplexed optical data signal. Thus the loss budget forfield DWDM DeMux404 may be 5.8 dB.

In some embodiments, an optical switch (e.g.,optical switch116 or optical switch308) may contribute to the loss budget experienced by an optical data signal is transmitted from the OCML headend to the outside plant or an optical data signal received at the OCML headend from the outside plant. This may be due to the fact that the optical switch may comprise one or more electronics that may cause the optical data signal to experience some loss in power as it is it switched from one connector to another in the OCML headend. Thus switch (headend)405 may cause the optical data signal to experience a 1.5 dB loss.

In some embodiments, there may be an optical passive component connecting the OCML headend to the outside plant. For instance, there may be a first fiber connection between the OCML headend and the optical passive component, and a second fiber connection between the optical passive component and the outside plant. This is depicted as passiveoptical component625 inFIG. 6 below. The optical passive component, may cause optical data signals transmitted between the OCML headend and the outside plant to experience some loss in power. The optical passive component may be a 3 dB optical passive component (i.e., 3 dB optical passive406) that may cause the optical data signals to experience a 3.5 dB loss.

In some embodiments, there may be two connectors at the OCML headend (e.g.,connector118 and connector150). Each may cause an optical data signal sent to a outside plant or received from the outside plant to experience a loss in power. Each connector may contribute a 0.3 dB loss resulting in the two connectors (connectors407) contributing a total loss of 0.6 dB. In some embodiments, a safety margin (e.g., safety margin408) of 3 dB may be included.

FIG. 5 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.FIG. 5 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 5,headend530 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM507), a first WDM (e.g., WDM505), a second WDM (e.g., WDM509), a GPON port (e.g., GPON PORT501), an XGPON/10GEPON port (e.g., XGPON/10GEPON PORT503), an EDFA (e.g., EDFA541), and anoptical switch508 to feed a primary optical fiber (e.g., Primary Fiber540) or secondary (backup) optical fiber (e.g., Secondary Fiber511).DWDM507 may be similar in functionality toDWDM106 andWDM505 andWDM509 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a outside plant (e.g., Outside plant550) or field hub. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

In one aspect,headend530 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS504) and twenty coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP506). 20×c 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP506 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP506 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend530 may be described by way of the processing of downstream optical data signals transmitted fromheadend530 to a outside plant (e.g., Outside plant550), and the processing of upstream optical data signals received from the outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM507 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., multi-wavelength downstream optical data signal547) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal547 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM507 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal547, may be input toWDM505.WDM505 may be a four port wave division multiplexer (WDM), or a four port circulator, that receives multi-wavelength downstream optical data signal547 onport542.WDM505 may function as a circulator and may output multi-wavelength downstream optical data signal538, onport540, toWDM509. Multi-wavelength downstream optical data signal538 may be substantially the same as multi-wavelength downstream optical data signal547.WDM509 may receive multi-wavelength downstream optical data signal538, and may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON534), on port548, a GPON signal, carried on a second fiber (e.g., GPON532), on port549, and may multiplex multi-wavelength downstream optical data signal538 with the XGPON/10GEPON and GPON signal. XGPON/10GEPON534 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm and 1260 nm-1280 nm range.GPON532 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 or 1310 nm.WDM509 outputs an egress optical data signal fromport542, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.WDM509 may multiplex multi-wavelength downstream optical data signal538, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM307 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal539) may be output onport542 ofWDM509 andoptical switch508 may switch egress optical data signal539 ontoprimary fiber540 or secondary fiber511 depending on the position ofswitch508. Egress optical data signal539 may be transmitted onprimary fiber540 to a first connector atoutside plant550, or may be transmitted on secondary fiber511 to a second connector atoutside plant550.Outside plant550 may include a MDM with the first connector and the second connector.

The operation ofoutside plant550 may be described by way of the processing of a downstream optical data signal received fromheadend530. Egress optical data signal539 may be received on the first or second connector atoutside plant550 based on a position ofoptical switch580, as ingress optical data signal582. That is ingress optical data signal582 may be similar to egress optical data signal539. Ingress optical data signal582 may be received byWDM513 viaport584.WDM513 may demultiplex ingress optical data signal582 into a multi-wavelength downstream optical data signal599, an XGPON/10GEPON optical data signal that may be output onport595 onto a first fiber (e.g., XGPON/10GEPON554), and/or a GPON optical data signal output onport596 onto a second fiber (e.g., GPON552). The XGPON/10GEPON optical data signal may be received on XGPON/10GEPON port553 and the GPON optical data signal may be received onGPON port551.

The multi-wavelength downstream optical data signal599 may be output onport597 and received byEDFA544. The multi-wavelength downstream optical data signal559 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedEDFA544 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, the gain of boosteroptical amplifier544 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain of boosteroptical amplifier544 may be G=e^(2αL), where α is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber540 and/or the length of secondary fiber511). Multi-wavelength upstream optical data signal599 may be amplified byEDFA544, andEDFA544 may output multi-wavelength downstream optical data signal598 toDWDM515.

DWDM515 may demultiplex the multi-wavelength downstream optical data signal589 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength downstream optical data signal598 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM515 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS512. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS512 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS512 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection. In some embodiments,DWDM515 may output one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., RPD DS527) to a remote physical (PHY) device (RPD) (e.g., RPD517).RPD517 may be similar toRemote PHY Node207 in functionality.RPD517 may convert the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into an electrical signal that may be transmitted over one or more coaxial cables.RPD517 may also convert one or more electrical signals into one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal for transmission to a transponder (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP514).

The operation ofoutside plant550 may be further described by way of the processing of an upstream optical data signal transmitted toheadend530. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP514 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP514 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP514 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM519 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength upstream optical data signal (e.g., multi-wavelength downstream optical data signal569) toport593 ofWDM513. In some embodiments,RPD517 may transmit one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., RPD UP537) to one or more of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP514. RPD UP537 may be 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals generated byRPD517 in response toRPD517 receiving electrical signals on coaxial cables connecting a remote physical (PHY) network (e.g., remote PHY network216) toDWDM519. The multi-wavelength upstream optical data signal569 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM519 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength upstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

WDM513 may be a five port wave division multiplexer (WDM), or a five port circulator, that receives a multi-wavelength upstream optical data signal onport593.WDM513 may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON554), onport595, a GPON signal, carried on a second fiber (e.g., GPON552), onport596, and may multiplex the multi-wavelength upstream optical data signal with the XGPON/10GEPON and GPON signal. XGPON/10GEPON554 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm range.GPON552 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm.WDM513 outputs an egress optical data signal fromport584, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.WDM513 may multiplex the multi-wavelength upstream optical data signal, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM507,515, and519 multiplex optical data signals. The egress optical data signal (e.g., egress optical data signal583) may be output onport584 ofWDM513 andoptical switch580 may switch egress optical data signal583 ontoprimary fiber540 or secondary fiber511 depending on the position ofswitch580. Egress optical data signal583 may be transmitted onprimary fiber540 to a first connector atheadend530, or may be transmitted on secondary fiber511 to a second connector atheadend530.

The operation ofheadend530 may be further described by way of the processing of an upstream optical data signal received fromoutside plant550. Egress optical data signal583 may be received on the first or second connector atheadend530 based on a position ofoptical switch508, as ingress optical data signal543. That is ingress optical data signal543 may be similar to egress optical data signal583. Ingress optical data signal543 may be received byWDM509 viaport542.

WDM509 may demultiplex ingress optical data signal543 into a multi-wavelength upstream optical data signal559, an XGPON/10GEPON optical data signal that may be output on port548 onto a first fiber (e.g., XGPON/10GEPON534), and/or a GPON optical data signal output on port549 onto a second fiber (e.g., GPON532). The XGPON/10GEPON optical data signal may be received on XGPON/10GEPON port503 and the GPON optical data signal may be received onGPON port501.

The multi-wavelength upstream optical data signal559 may be output onport545 and received byEDFA541. The multi-wavelength upstream optical data signal559 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedEDFA541 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofEDFA544. Multi-wavelength upstream optical data signal559 may be amplified byEDFA541, andEDFA541 may output multi-wavelength upstream optical data signal529 toWDM505.WDM505 may receive the multi-wavelength upstream optical data signal520 onport543 ofWDM505.WDM505 may output multi-wavelength upstream optical data signal536 which is substantially the same as multi-wavelength upstream optical data signal529.WDM505 may function as a circulator when receiving multi-wavelength upstream optical data signal529 onport543 and outputting multi-wavelength upstream optical data signal536 onport542. Multi-wavelength upstream optical data signal536 may be received byDWDM507.

The multi-wavelength upstream optical data signal536 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM507 may demultiplex the multi-wavelength upstream optical data signal536 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength upstream optical data signal536 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM507 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP506. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP506 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP506 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 6 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.FIG. 6 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 6,headend630 is a smart integrated OCML headend, which is a circuit, comprising a AWG (e.g., AWG607), a first WDM (e.g., WDM605), a second WDM (e.g., WDM609), a GPON port (e.g., GPON PORT601), an XGPON/10GEPON port (e.g., XGPON/10GEPON PORT603), a first EDFA (e.g., EDFA641), a second EDFA (e.g., EDFA643), and anoptical switch613 to feed a primary optical fiber (e.g., Primary Fiber617) or secondary (backup) optical fiber (e.g., Secondary Fiber627).AWG607 may be similar in functionality toDWDM106 andWDM605 andWDM609 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a outside plant (e.g., Outside plant650) or field hub. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

In one aspect,headend630 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS604) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP606). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS604 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP606 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS504 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP606 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend630 may be described by way of the processing of downstream optical data signals transmitted fromheadend630 to a outside plant (e.g., Outside plant650) or field hub, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS604 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS604 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS604 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

AWG607 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g.,638) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal638 may be a 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,AWG607 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal638, may be input toWDM605.WDM605 may be a five port wave division multiplexer (WDM), or a five port circulator, that receives multi-wavelength downstream optical data signal638 on port602.WDM605 may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON634), on port610, a GPON signal, carried on a second fiber (e.g., GPON632), onport667, and may multiplex multi-wavelength downstream optical data signal638 with the XGPON/10GEPON and GPON signal. XGPON/10GEPON634 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm range.GPON632 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm or 1310 nm.WDM605 outputs an egress optical data signal fromport615, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.WDM605 may multiplex multi-wavelength downstream optical data signal638, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way AWG607 multiplexes optical data signals.

WDM605 may output multi-wavelength downstream optical data signal639 to an EDFA (e.g., EDFA641). A gain of the EDFA may be based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, the EDFA may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, thegain EDFA641 may be G=e^(2αL), where α is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber617 and/or the length of secondary fiber627). Multi-wavelength downstream optical data signal639 may be amplified byEDFA641, andEDFA641 may output multi-wavelength downstream optical data signal640 toport615 ofWDM609.WDM609 outputs an egress optical data signal from port616, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.

Egress optical data signal620 byWDM609 andoptical switch613 may switch egress optical data signal620 ontoprimary fiber617 orsecondary fiber627 depending on the position ofswitch613. Egress optical data signal620 may be transmitted onprimary fiber617 toport621 at passiveoptical component625, or may be transmitted onsecondary fiber627 toport631 at passiveoptical component625. Passiveoptical component625 may output ingress optical data signal656 fromport629 toport697 atWDM673.

Ingress optical data signal656 may be received byWDM673 viaport697.WDM673 may demultiplex ingress optical data signal656 into a mutli-wavelength downstream optical data signal659, an XGPON/10GEPON optical data signal that may be output onport699 onto a first fiber (e.g., XGPON/10GEPON654), and/or a GPON optical data signal output onport698 onto a second fiber (e.g., GPON652). The XGPON/10GEPON optical data signal may be received on XGPON/10GEPON port653 and the GPON optical data signal may be received onGPON port651.

The multi-wavelength downstream optical data signal659 may be output on port696 and received by array waveguide gratings (AWG)AWG675. The multi-wavelength downstream optical data signal659 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.AWG675 may demultiplex the multi-wavelength upstream optical data signal659 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength downstream optical data signal659 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.AWG675 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS612. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS612 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS612 may transmit the twenty SONET/SDH optical data signals to a RPD (e.g., RPD677) on the SONET/SDH optical network connection. In some embodiments,AWG675 may output one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., RPD DS627)RPD677.RPD677 may be similar toRemote PHY Node207 in functionality.RPD677 may convert the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into an electrical signal that may be transmitted over one or more coaxial cables.RPD617 may also convert one or more electrical signals into one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal for transmission to a transponder (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP614).

The operation ofoutside plant650 may be further described by way of the processing of an upstream optical data signal transmitted toheadend630. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP614 may receive a SONET/SDH optical data signal fromRPD677 and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP614 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP614 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

AWG675 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength upstream optical data signal (e.g., multi-wavelength upstream optical data signal658) comprising the twenty corresponding second optical data signals onto a fiber. In some embodiments,RPD677 may transmit one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbEoptical data signals (e.g., RPD UP637) to one or more of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP614.RPD UP637 may be 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals generated byRPD677 in response toRPD677 receiving electrical signals on coaxial cables connecting a remote physical (PHY) network (e.g., remote PHY network216) toAWG675. The multi-wavelength upstream optical data signal658 may be a coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,AWG675 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength upstream optical data signal658, may be input toWDM673.WDM673 may be a four port wave division multiplexer (WDM), or a four port circulator, that receives multi-wavelength upstream optical data signal658 on port696.WDM673 may also receive an XGPON/10GEPON signal, carried on a first fiber (e.g., XGPON/10GEPON654), onport699, a GPON signal, carried on a second fiber (e.g., GPON652), onport698, and may multiplex multi-wavelength upstream optical data signal658 with the XGPON/10GEPON and GPON signal. XGPON/10GEPON654 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm range.GPON652 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm or 1310 nm.WDM673 outputs an egress optical data signal fromport697, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and/or GPON optical data signals.WDM673 may multiplex multi-wavelength upstream optical data signal658, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way AWG675 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal657) may be output onport697 ofWDM673 to port629 of passiveoptical component625. Passiveoptical component625 may switch egress optical data signal657 ontoprimary fiber617 orsecondary fiber627 depending on a position of a switch in passiveoptical component625. Egress optical data signal657 may be transmitted onprimary fiber617 to a first port (e.g., port615) atheadend630, or may be transmitted onsecondary fiber627 to a second port (e.g., port623) atheadend630.

The operation ofheadend630 may be further described by way of the processing of an upstream optical data signal received fromoutside plant650. Egress optical data signal657 may be received on the first or second connector atheadend630 based on a position ofoptical switch613, as ingress optical data signal611. That is ingress optical data signal611 may be similar to egress optical data signal657. Ingress optical data signal611 may be received byWDM609 via port616.

WDM609 may demultiplex ingress optical data signal611 into a multi-wavelength upstream optical data signal619. The multi-wavelength upstream optical data signal619 may be output on port618 and received byEDFA643. The multi-wavelength upstream optical data signal619 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedEDFA643 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofEDFA641. Multi-wavelength upstream optical data signal619 may be amplified byEDFA643, andEDFA643 may output multi-wavelength upstream optical data signal633 toWDM605.WDM605 may receive the multi-wavelength upstream optical data signal633 onport608 ofWDM605.WDM605 may output multi-wavelength upstream optical data signal636 which is substantially the same as multi-wavelength upstream optical data signal633.WDM605 may function as a circulator when receiving multi-wavelength upstream optical data signal633 onport608 and outputting multi-wavelength upstream optical data signal636 on port602. Multi-wavelength upstream optical data signal636 may be received byAWG607.

The multi-wavelength upstream optical data signal636 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.AWG607 may demultiplex the multi-wavelength upstream optical data signal636 into individual optical data signals in accordance with the individual wavelengths of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. More specifically, the multi-wavelength upstream optical data signal636 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.AWG607 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP606. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP606 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP606 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 7 depicts different passive optical network (PON) transceiver parameters associated with downstream transmitting circuits and upstream transmitting circuits, in accordance with the disclosure.Parameters700, comprise a wavelength column (i.e., wavelength701), a transmission (Tx) power column (i.e., Tx power702), a dispersion penalty column (i.e., dispersion power703), a loss budget column (i.e., loss budget705), and a minimum receive power column (i.e., minimum receive power709) for different passive optical network (PON) transceivers (i.e., GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731).

Wavelength701 may include the wavelength of a downstream optical data signal (i.e., downstream712, downstream722, and downstream732) transmitted by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend to a corresponding PON transceiver at an outside plant.Wavelength701 may include the wavelength of an upstream optical data signal (i.e., upstream713, upstream723, and upstream733) received by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend from a corresponding PON transceiver at a outside plant. The downstream optical data signal may be an optical data signal sent from an OCML headend to a outside plant, as disclosed herein. The upstream optical data signal may be an optical data signal received at the OCML headend from an outside plant, as disclosed herein.

Tx power702 may include the transmission power of the downstream optical data signal (i.e., downstream712, downstream722, and downstream732) from each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend to a corresponding PON transceiver at an outside plant.Tx power702 may include the transmission power of the upstream optical data signal (i.e., upstream713, downstream723, and downstream733) transmitted by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an outside plant to a corresponding PON transceiver at an OCML headend.

Dispersion penalty703 may include a power dispersion penalty associated with the downstream optical data signal (i.e., downstream712, downstream722, and downstream732) being transmitted by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 on a fiber from an OCML headend to a corresponding PON transceiver at a outside plant.Dispersion penalty703 may include a power dispersion penalty associated with the upstream optical data signal (i.e., downstream713, downstream723, and downstream733) being received by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend from a corresponding PON transceiver at a outside plant.

In some embodiments, an optical data signal may experience dispersion as it travels through an optical fiber. The dispersion penalty may be based at least in part on a bandwidth of the optical fiber, a dispersion constant for a given wavelength carrying the optical data signal, the length of the optical fiber, and a wavelength spread of a laser generating the optical data signal. More specifically the dispersion penalty may be determined by the expression PP_D(B, D, L, σ_λ)=5*log [1+2*π*(B*D*L*σ_λ)²]. B is the bandwidth of the optical fiber carrying the optical data signal, D is the dispersion constant, L is the length of the optical fiber, and σ_Ais the wavelength spread of the laser. B and L may be constants that are determined during a design of fiber to the home (FTTH) network like the one depicted inFIG. 2. D may be based at least in part a zero dispersion wavelength for the optical data signal, a dispersion wavelength of the optical data signal, and a slope of the dispersion characteristic for the zero dispersion wavelength of the optical data signal. Specifically, D may be equal to

$\frac{{\mathrm{<figure-callout\; label="S"\; filenames="US10999656-20210504-D00008.png,US10999656-20210504-D00016.png"\; state="\{\{state\}\}">S</figure-callout>}}_0}{4}*\left(\lambda -\frac{{\mathrm{<figure-callout\; label="\lambda "\; filenames="US10999656-20210504-D00008.png,US10999656-20210504-D00016.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}_0^4}{{\lambda }^3}\right),$
wherein S₀is the slope of the dispersion characteristic for the zero dispersion wavelength (λ₀) of the optical data signal. The zero dispersion wavelength may be the wavelength at which material dispersion and waveguide dispersion cancel one another out. λ may be the dispersion wavelength of the optical data signal. The units of S₀may be picoseconds per the product of nanometers squared and kilometer

$\left(i.e.,<figure-callout\; label="\; ps\; nm"\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}"></figure-callout>\frac{\mathrm{ps}}{{\mathrm{nm}}^{}}\frac{{}^2*\mathrm{km}}{}\right).$

Loss budget705 may include a loss budget associated with the downstream optical data signal (i.e., downstream712, downstream722, and downstream732) being transmitted by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend to a corresponding PON transceiver at a outside plant along a fiber connecting the OCML headend and outside plant.Loss budget705 may include a loss budget associated with the upstream optical data signal (i.e., downstream713, downstream723, and downstream733) being received by each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731 at an OCML headend from a corresponding PON transceiver at a outside plant along a fiber connecting the OCML headend and outside plant.

Minimum receivepower709 may include a minimum receive power necessary for each of PON transceivers GPON C+711, XGPON/10GEPON N2a721, or XGPON/10GEPON N1731, at a outside plant, to correctly decode one or more bits received from a corresponding PON transceiver at an OCML headend in a downstream optical data signal (i.e., downstream712, downstream722, and downstream732). For instance, a minimum receive power level may be necessary for each of PON transceivers GPON C+711, XGPON/10GEPON N2a, or XGPON/10GEPON N1731 to correctly detect a bit value of “1”, at the outside plant, when a bit value of “1” is transmitted by a corresponding PON transceiver at an OCML headend. Minimum receivepower709 may include a minimum receive power necessary for each of PON transceivers GPON C+711, XGPON/10GEPON N2a, at an OCML headend, to correctly decode one or more bits received from a corresponding transceiver at a outside plant in an upstream optical data signal. For instance, a minimum receive power level may be necessary for each of PON transceivers GPON C+711, XGPON/10GEPON N2a, or XGPON/10GEPON N1731 to correctly detect a bit value of “1”, at the OCML headend, when a bit value of “1” is transmitted by a corresponding PON transceiver at the outside plant.

In some embodiments, a GPON C+ transceiver (i.e., GPON C+711), at an OCML headend, may transmit a downstream (i.e., downstream712) optical data signal with a wavelength (i.e., wavelength701) of 1490 nanometers, a Tx power (i.e., Tx power702) between 3 and 7 decibel-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 1 decibel, a loss budget (i.e., loss budget705) of 32 decibels, and a minimum receive power (i.e., minimum receive power709) of −30 decibels to a GPON C+ transceiver at a outside plant.

In some embodiments, a GPON C+ transceiver (i.e., GPON C+711), at a outside plant, may transmit an upstream (i.e., upstream713) optical data signal, with a wavelength (i.e., wavelength701) of 1310 nanometers, a Tx power (i.e., Tx power702) between 0.5 and 5 decibel-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 0.5 decibel, a loss budget (i.e., loss budget705) of 32 decibels, and a minimum receive power (i.e., minimum receive power709) of −32 decibels to a GPON C+ transceiver at an OCML headend.

In some embodiments, an XGPON/10GEPON N2a transceiver (i.e., XGPON/10GEPON N2a721), at an OCML headend, may transmit a downstream (i.e., downstream722) optical data signal with a wavelength (i.e., wavelength701) of 1575 nanometers, a Tx power (i.e., Tx power702) between 4 and 8 decibel-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 1 decibel, a loss budget (i.e., loss budget705) of 31 decibels, and a minimum receive power (i.e., minimum receive power709) of −28 decibels to an XGPON/10GEPON N2a transceiver at a outside plant.

In the same, or a similar embodiment, an XGPON/10GEPON N2a transceiver (i.e., XGPON/10GEPON N2a721), at a outside plant, may transmit an upstream (i.e., upstream723) optical data signal, with a wavelength (i.e., wavelength701) of 1270 nanometers, a Tx power (i.e., Tx power702) between 2 and 7 decible-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 0.5 decibel, a loss budget (i.e., loss budget705) of 31 decibels, and a minimum receive power (i.e., minimum receive power709) of −29.5 decibels to an XGPON/10GEPON N2a transceiver at an OCML headend.

In some embodiments, an XGPON/10GEPON N1 transceiver (i.e., XGPON/10GEPON N1731), at an OCML headend, may transmit a downstream (i.e., downstream732) optical data signal with a wavelength (i.e., wavelength701) of 1575 nanometers, a Tx power (i.e., Tx power702) between 2 and 6 decibel-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 1 decibel, a loss budget (i.e., loss budget705) of 31 decibels, and a minimum receive power (i.e., minimum receive power709) of −28 decibels to an XGPON/10GEPON N1 transceiver at a outside plant.

In the same, or a similar embodiment, an XGPON/10GEPON N1 transceiver (i.e., XGPON/10GEPON N1731), at an outside plant, may transmit an upstream (i.e., upstream733) optical data signal, with a wavelength (i.e., wavelength701) of 1270 nanometers, a Tx power (i.e., Tx power702) between 2 and 7 decibel-milliwatts, a dispersion penalty (i.e., dispersion penalty703) of 0.5 decibel, a loss budget (i.e., loss budget705) of 29 decibels, and a minimum receive power (i.e., minimum receive power709) of −27.5 decibels to an XGPON/10GEPON N1 transceiver at an OCML headend.

FIG. 8 depicts a graphical representation of wavelengths used to transport one or more signals, in accordance with the disclosure. OCMLoptical wavelengths801 illustrate the different wavelengths of the optical data signals described herein. For GPON optical data signals disclosed herein, a wavelength of 1310 nm may be used to transmit an upstream GPON optical data signal from a outside plant to an OCML headend. For GPON optical data signals disclosed herein, a wavelength of 1490 nm may be used to transmit a downstream GPON optical data signal from the OCML headend to the outside plant. For 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals disclosed herein, a wavelength between 1530 and 1565 nm may be used to transmit an upstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal to the OCML headend from the outside plant, and to transmit a downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal to the outside plant from the OCML headend. In some embodiments, the upstream XGPON/10GEPON optical data signals disclosed herein may have wavelengths between 1260 nm and 1280 nm (e.g., XGPON/10GEPON802). In some embodiments, the downstream XGPON/10GEPON optical data signals disclosed herein may have wavelengths between 1571 nm and 1591 nm.

FIG. 9 depicts a stimulated Raman scattering (SRS) diagram, in accordance with the disclosure.Raman gain spectrum900 may be Raman gain coefficients for an optical fiber comprised of silica and Germania-oxide (GeO₂).Raman gain spectrum900 may be a plot of Raman gain coefficients against different wavelengths (i.e., wavelength903). SRS is a nonlinear process where higher frequency optical channels are depleted and lower frequency optical channels are amplified. With each optical channel being modulated, the intensity of higher frequency optical data signals modulate the intensity of lower frequency optical data signals. As a result, SRS may lead to optical crosstalk between channels. The optical crosstalk due to SRS may be referred to as SRS optical crosstalk, and may be defined by the following expression

${\mathrm{XT}}_{\mathrm{SRS},i}={\mathrm{<figure-callout\; label="P"\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">P</figure-callout>}}^2\sum _{k\ne i}\frac{g_{i,\mathrm{<figure-callout\; label="k"\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">k</figure-callout>}}^2}{{\Delta }_{\mathrm{eft}}}\left({\left(1-e^{-\alpha L}\right)}^2+4e^{-\alpha L}{\mathrm{<figure-callout\; label="sin"\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\left(\frac{\Omega d_{i,k}L}{2}\right)\right)/\left({\mathrm{<figure-callout\; label="\alpha "\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}^2+{\mathrm{<figure-callout\; label="\Omega "\; filenames="US10999656-20210504-D00004.png,US10999656-20210504-D00008.png"\; state="\{\{state\}\}">\Omega </figure-callout>}}^2{d}_{i,k}^2\right).$
That is the optical crosstalk experienced on a channel “i” (XT_SRS,i) is based at least in part on the square of the optical fiber launch power per channel (P) at which an optical data signal is transmitted. The optical crosstalk may also based at least in part on Raman gain coefficients (g_i,k²) between channel “i” and a channel “k”. The Raman gain coefficients may be based at least in part on a Raman gain slope and the frequency at which optical data signals on channel “i” are propagating and the frequency at which optical data signals on channel “k” are propagating. The optical crosstalk may also be based at least in part on a fiber loss (a) and length (L) of the optical fiber. The optical crosstalk may also be based at least in part on a subcarrier modulation frequency (Ω) and a group velocity mismatch between optical data signals propagating on channel “i” and optical data signals propagating on channel “k” (d_i,k).

Depending on the wavelength separation between the optical data signals propagating on channel “i” and the optical data signals propagating on channel “k”, polarization states of the optical data signals in channels “i′” and “k”, the optical fiber launch powers for channels “i′” and “k” SRS optical crosstalk may occur which depletes shorter (pump depletion902) wavelengths (e.g.,GPON 1490 nm) and amplifies the higher (stokes) wavelengths resulting in signal degradation for certain optical data signals (e.g., coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal degradation 901). In some embodiments, the effect is on lower RF frequencies carried on longer wavelength optical data signals. Because of this interference from a GPON optical data signal with a wavelength of 1490 nm may cause interference or signal degradation of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal with a wavelength of 1560 nm. In some embodiments, the SRS optical crosstalk may be 35 dB which may result in a tolerable BER.

FIG. 10 depicts a schematic illustration of wavelength and optical fiber monitoring of cascaded OCML headends in accordance with the disclosure.Headend1001 is a smart integrated OCML headend, which is a circuit, comprising one or more EDFAs (e.g.,Booster Optical amplifiers1012 and1019), a DWDM (e.g., DWDM1007), one or more WDMs (e.g.,WDM1008 and1023), one or more DCMs (e.g., DCM1018 and1015), and anoptical switch1027 to feed a primary optical fiber (e.g., Primary Fiber1031) or secondary (backup) optical fiber (e.g., Secondary Fiber1032). The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a outside plant or field hub housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

In one aspect,headend1001 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1003) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1004). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1003 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1004 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths.Headend1001 may comprise twoPON1002 connectors, one of which may be a GPON connector (e.g., GPON1006) and one of which may be an XGPON/10GEPON connector (e.g., XGPON/10GEPON1005).Headend1001 may also comprise two wavelength-monitoring ports (e.g., wavelength-monitoring ports1039), a primary optical fiber (e.g., primary optical fiber1031) and a secondary optical fiber (e.g., secondary optical fiber1032) that transmit and receive a plurality of multi-wavelength 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON optical signals. Primaryoptical fiber1031 and secondaryoptical fiber1032 may transmit a first plurality of multi-wavelength coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON optical signals fromheadend1001 to a outside plant (not illustrated inFIG. 10), and may receive a second plurality of multi-wavelength 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON optical signals from the outside plant.

The operation ofheadend1001 may be described by way of the processing of downstream optical data signals transmitted fromheadend1001 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1003 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1003 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1003 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1007 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1098) comprising the twenty corresponding second optical data signals onto a fiber. More specifically,DWDM1007 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength downstream optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1098, may be input to a WDM (e.g. WDM1008).WDM1008 may be a three port wave division multiplexer (WDM), or a three port circulator, that receives 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1098 onport1010 and outputs 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1098 onport1009 as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1013. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1013 may be substantially the same as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1098 becauseWDM1008 may function as a circulator when 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1098 is input onport1010.

WDM 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1013 may be input to an EDFA (e.g., booster optical amplifier1012). A gain of the booster optical amplifier (e.g., booster optical amplifier1012) may be based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, the gain of boosteroptical amplifier1012 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain of boosteroptical amplifier1012 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1031 and/or the length of secondary fiber1032). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1013 may be amplified by boosteroptical amplifier1012, and boosteroptical amplifier1012 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1017 to DCM1018.

10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1017 may be input into a DCM (e.g., DCM1012) to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1017 may experience after being amplified by an EDFA and multiplexed by a WDM, with other optical data signals, that are downstream from the DCM. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend1001 over afiber connecting headend1001 to a field hub or outside plant. In some embodiments, DCM1018 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments, DCM1018 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically, DCM1018 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.

WDM1023 may be a WDM that may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1022 with one or more PON signals carried on XGPON/10GEPON1005 andGPON1006. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1022 may be a multi-wavelength optical data signal, wherein the wavelengths comprise the same wavelengths as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1022. In some embodiments, the wavelengths of the multi-wavelength optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1022 may be within the conventional c band of wavelengths, which may include wavelengths within the 1520 nm-1565 nm range. XGPON/10GEPON1005 may be a fiber carrying an XGPON/10GEPON optical data signal with a wavelength within the 1571 nm-1591 nm or 1260 nm-1280 nm range.GPON1006 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm or 1310 nm. The XGPON/10GEPON optical signal may be input toWDM1023 onport1021 and the GPON optical signal may be input toWDM110 onport160.WDM1023 outputs an egress optical data signal fromport1025, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, XGPON/10GEPON, and GPON optical data signals.WDM1023 may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1022, the XGPON/10GEPON optical data signal, and GPON optical data signal thesame way DWDM1007 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal1020) may be output onport1025 ofWDM1023 andoptical switch1027 may switch egress optical data signal1020 out ofconnector1029 orconnector1034. In some embodiments,connector1029 may be a primary connector andconnector1034 may be a secondary connector or a backup connector.Wavelength monitoring connector1039 may connectconnector1028 to a first port of wavelength-monitoring ports1039, andwavelength monitoring connector1034 may connectconnector1035 to a second port of wavelength-monitoring ports1039. Wavelength-monitoring ports1039 may monitor the wavelengths in egress optical data signal1020 viaconnector1029 orconnector1034 depending on the position ofswitch1027. Egress optical data signal1020 may exitheadend1001 either viaconnector1030 connected toprimary fiber1031 or viaconnector1033 connected tosecondary fiber1032 depending on the position ofswitch1027. Egress optical data signal1020 may be transmitted onprimary fiber1031 to a first connector in the field hub or outside plant, or may be transmitted onsecondary fiber1032 to a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

The operation ofheadend1001 may be described by way of the processing of upstream optical data signals received atheadend1001 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, XGPON/10GEPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber1031 orsecondary fiber1032 depending on the position ofswitch1027. Because the multi-wavelength ingress optical data signal is routed toport1025 ofWDM1023, and is altered negligibly betweenconnector1028 andport1025 orconnector1035 andport1025, depending on the position ofswitch1027, the multi-wavelength ingress optical data signal may be substantially the same as ingress optical data signal1026. The multi-wavelength ingress optical data signal may traverseconnector1028 andswitch1027, before enteringWDM1023 viaport1025 ifswitch1027 is connected toconnector1028. The multi-wavelength ingress optical data signal may traverseconnector1035 andswitch1027, before enteringWDM1023 viaport1025 ifswitch1027 is connected to connector1350.WDM1023 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, XGPON/10GEPON optical data signals, and/or GPON optical data signals from ingress optical data signal1026.WDM1023 may transmit the one or more XGPON/10GEPON optical data signals along XGPON/10GEPON1005 to one ofPON connectors1002 viaport1024.WDM1023 may transmit the one or more GPON optical data signals alongGPON1006 to one ofPON connectors1002 viaport1021.WDM1023 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., signal1038) out ofport1037 toBOA1019.

A gain ofBOA1019 may be based at least in part on a distance that the SONET/SDH egress optical data signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment on the SONET/SDH optical network connection. For instance, the gain ofBOA1019 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain ofBOA1019 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length of the fiber of the SONET/SDH optical network connection). Signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE1038 may be amplified byBOA1019, andBOA1019 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 toDCM1015.

The wavelength of 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 may be within the conventional c band of wavelengths, which may include wavelengths within the 1520 nm-1565 nm range. The one or more XGPON/10GEPON optical data signals may have a wavelength within the 1571 nm-1591 nm or 1260 nm-1280 nm range, and the one or more GPON optical data signals may have a wavelength of 1490 nm.

In some embodiments,DCM1015 may be configured to balance positive and/or negative dispersion that may be introduced to a SONET/SDH egress optical data signal that may enterheadend1001 from 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1004. The SONET/SDH egress optical data signal may be an upstream signal from a field hub or outside plant destined for a MTC. For example, a customer premise may be connected to the field hub or outside plant and may send one or more packets via a SONET/SDH network to the field hub or outside plant which may in turn transmit the one or more packets using 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals toheadend1001. The one or more packets may be destined for a company web server connected to the MTC via a backbone network. Becauseheadend1001 may be collocated in a STC that is connected to the MTC via an optical ring network, wherein the connection between the STC and MTC is an SONET/SDH optical network connection,DCM1015 may be configured to compensate for positive and/or negative dispersion on the SONET/SDH optical network connection. That isDCM1015 may be configured to reduce temporal broadening of the SONET/SDH egress optical data signal or temporal contraction of the SONET/SDH egress optical data signal.DCM1015 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1016 and my output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 toWDM1008.

WDM1008 may receive 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 onport1011, and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1009 onport1010 as a multi-wavelength upstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1009). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1098 is substantially the same as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 becauseWDM1008 may function as a circulator when 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 is input toport1011. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1009 may be received byDWDM1007, and DWDM may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals from 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1009. Because 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1009 is a dispersion compensated amplified version of the multi-wavelength ingress optical data signal,DWDM1007 may demultiplex the one or more optical data signals into individual optical data signals in accordance with the individual wavelengths of any coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals in the multi-wavelength ingress optical data signal. More specifically, 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1009 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1007 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1004. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1004 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1014 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

Headend1086 and the components therein may be similar in function to the components inheadend1001. Optical line monitor1011 ports c and g may be connected to wavelength-monitoring ports1039 and optical line monitor1011 ports b and f may be connected to wavelength-monitoring ports1084.Optical line monitor1011 may be a device that monitors egress optical data signals transmitted onprimary fiber1031 orprimary fiber1070 and ingress optical data signals received onprimary fiber1031 orprimary fiber1070.Optical line monitor1011 may also monitor egress optical data signals transmitted onsecondary fiber1032 orsecondary fiber1071 and ingress optical data signals received onsecondary fiber1032 orsecondary fiber1071.

FIG. 11 a schematic illustration of wavelength and optical fiber monitoring of an OCML headend in accordance with the disclosure.Headend1102 and the components therein may be similar in function to the components inheadend1001. Optical line monitor1011 ports a and e may be connected to wavelength-monitoring ports1178.

FIG. 12 depicts an access network diagram of an OCML headend comprising wavelength division multiplexers (WDMs), a dense wavelength division multiplexer (DWDM), and optical amplifiers, in accordance with the disclosure.FIG. 12 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 12,headend1201 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM1205), a first WDM (e.g., WDM1210), a second WDM (e.g., WDM1220), a GPON/EPON connector (e.g., GPON/EPON1218), a booster amplifier BOA (e.g., BOA1215), an optical pre-amplifier (OPA) (e.g., OPA1214), anoptical switch1226 to feed a primary optical fiber (e.g., Primary Fiber1235) via a primary variable optical attenuator (VOA) (e.g., VOA1231) or secondary (backup) optical fiber (e.g., Secondary Fiber1236) via a secondary variable optical attenuator (VOA) (e.g., VOA1232).DWDM1205 may be similar in functionality toDWDM106 andWDM1210 andWDM1220 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

The EPON signals may operate with the same optical frequencies as GPON and time division multiple access (TDMA). The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions.

EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON may not use a carrier sense multiple access (CSMA)/collision detection (CD) access method used in other versions of Ethernet.

There is a 10-Gbit/s Ethernet version designated as 802.3av. The line rate may be 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1571 to 1591 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

In one aspect,headend1201 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1203) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1204). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1203 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1204 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1203 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1204 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend1201 may be described by way of the processing of downstream optical data signals transmitted fromheadend1201 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1203 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1203 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1203 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1205 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1206) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1206 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1205 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1206, may be input toWDM1210.WDM1210 may be a three port circulator, that receives multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1206 onport1208, and outputs multi-wavelength downstream optical data signal coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1206, onport1211 as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1213 toBOA1215.

BOA1215 may have a gain that is based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance,BOA1215 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, thegain BOA1215 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1235 and/or the length of secondary fiber1236). Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1213 may be amplified byBOA1215, andBOA1215 may output multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1216 toport1217 ofWDM1220.WDM1220 outputs an egress optical data signal fromport1219, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, EPON, and/or GPON optical data signals. The EPON and/or GPON optical data signals may be received on a GPON/EPON connector (e.g., GPON/EPON1218) fromPON port1202.

Egress optical data signal1225 may be output byWDM1220 andoptical switch1226 may switch egress optical data signal1225 ontoconnector1228 orconnector1227 depending on the position ofswitch1226. In some embodiments,connector1228 may be a primary connector andconnector1227 may be a secondary connector or a backup connector.Wavelength monitoring connector1230 may connectconnector1228 to a first port of wavelength-monitoring ports1237, and wavelength monitoring connector1229 may connectconnector1227 to a second port of wavelength-monitoring ports1237. Wavelength-monitoring ports1237 may monitor the wavelengths in egress optical data signal1225 viaconnector1228 orconnector1227 depending on the position ofswitch1226. Egress optical data signal1225 may exitheadend1201 either viaconnector1228 connected toprimary fiber1235, as egress optical data signal1240, or viaconnector1227 connected tosecondary fiber1236, as egress optical data signal1241, depending on the position ofswitch1226. Egress optical data signal1225 may be transmitted as, egress optical data signal1240, onprimary fiber1235 to a first connector in the field hub or outside plant. Egress optical data signal may be transmitted as, egress optical data signal1241, onsecondary fiber1236 to a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

Variable optical attenuator (VOA)1231 andVOA1232 may be used to reduce the power levels of egress optical data signal1225 or ingress optical data signal1224. The power reduction may done by absorption, reflection, diffusion, scattering, deflection, diffraction, and dispersion, of egress optical data signal1225 or ingress optical data signal1224.VOA1231 andVOA1232 typically have a working wavelength range in which they absorb all light energy equally. In someembodiments VOA1231 andVOA1232 utilize a length of high-loss optical fiber, that operates upon its input optical signal power level in such a way that its output signal power level is less than the input level. For example, egress optical data signal1225 may have an input power level toVOA1231 that may be greater than the output power level of egress optical data signal1240 as it is output fromVOA1231. Similarly if egress optical data signal1225 is transmitted onconnector1227, egress optical data signal1225 may have an input power level toVOA1232 that may be greater than the output power level of egress optical data signal1241. In some embodiments, the output power level of egress optical data signal1240 may be greater than the output power level of egress optical data signal1241, and vice versa. The difference in output power levels between egress optical data signal1240 and egress optical data signal1241 may depend on the mode ofprimary fiber1235 andsecondary fiber1236.VOA1232 may have a similar functionality to that haveVOA1231.

The variability of the output power level ofVOA1231 andVOA1232 may be achieved using a fiber coupler, where some of the power is not sent to the port that outputs, but to another port. Another possibility is to exploit variable coupling losses, which are influenced by variable positioning of a fiber end. For example, the transverse position of the output fiber or the width of an air gap between two fibers may be varied, obtaining a variable loss without a strong wavelength dependence. This principle may be used for single-mode fibers.VOA1231 andVOA1232 may be based on some piece of doped fiber, exhibiting absorption within a certain wavelength range.

The operation ofheadend1201 may be described by way of the processing of upstream optical data signals received atheadend1201 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber1235 orsecondary fiber1236 depending on the position ofswitch1226.

Because the multi-wavelength ingress optical data signal is routed toport1223 ofWDM1220, and is altered negligibly betweenconnector1228 andport1223 orconnector1227 andport1223, depending on the position ofswitch1226, the multi-wavelength ingress optical data signal may be substantially the same as ingress optical data signal1224. The multi-wavelength ingress optical data signal may traverseconnector1228 andswitch1226, before enteringWDM1220 viaport1223 ifswitch1226 is connected toconnector1228. The multi-wavelength ingress optical data signal may traverseconnector1227 andswitch1226, before enteringWDM1220 viaport1223 ifswitch1226 is connected toconnector1227.WDM1220 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from ingress optical data signal1224.WDM1220 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON1218 toPON connector1202 viaport1219.WDM1220 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1222) out of port1221 to OPA1214.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1222 may be received by OPA1214. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1222 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associated OPA1214 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofBOA1215. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1222 may be amplified by OPA1214, and OPA1214 may output multi-wavelength upstream optical data signal1212 toWDM1210.

WDM1210 may receive the multi-wavelength upstream optical data signal1212 onport1209 ofWDM1210, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 toDWDM1205. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 are substantially the same as multi-wavelength upstream optical data signal1212.WDM1210 may function as a circulator when receiving multi-wavelength upstream optical data signal1212 onport1209 and outputting the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 onport1208. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 may be received byDWDM1205.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1205 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1207 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1205 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1204. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1204 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbEoptical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1204 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 13 depicts an access network diagram of an OCML headend comprising WDMs, a DWDM, optical amplifiers, and dispersion control modules (DCMs), in accordance with the disclosure.FIG. 13 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 13,headend1301 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM1305), a first WDM (e.g., WDM1313), a second WDM (e.g., WDM1319), a third WDM (e.g., WDM1323), a GPON/EPON connector (e.g., GPON/EPON1324), a booster amplifier BOA (e.g., BOA1316), an optical pre-amplifier (OPA) (e.g., OPA1342), a variable optical attenuator (VOA) (e.g., VOA1321), anoptical switch1326 to feed a primary optical fiber (e.g., Primary Fiber1330) or secondary (backup) optical fiber (e.g., Secondary Fiber1331), and a dispersion control module (DCM) (e.g., DCM1308).DWDM1305 may be similar in functionality toDWDM106 andWDM1313,WDM1319, andWDM1323 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

The EPON signals may operate with the same optical frequencies as GPON and time division multiple access (TDMA). The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions. EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON may not use a carrier sense multiple access (CSMA)/collision detection (CD) access method used in other versions of Ethernet. There is a 10-Gbit/s Ethernet version designated as 802.3ay. The line rate may be 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1575 to 1591 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

In one aspect,headend1301 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1303) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1304). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1303 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1304 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1303 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1304 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend1301 may be described by way of the processing of downstream optical data signals transmitted fromheadend1301 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1303 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1303 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1303 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1305 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1307) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1307 may be a coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1305 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1307, may be input toDCM1308. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1307 may be input intoDCM1308 to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1307 may experience after being amplified byBOA1316 and multiplexed byWDM1323, with other optical data signals, that are downstream from the DCM. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend1301 over afiber connecting headend1301 to a field hub or outside plant. In some embodiments,DCM1308 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments,DCM1308 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically,DCM1308 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.DCM1308 may output a dispersion controlled version of 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1307 as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1310.

WDM1313 may be a three port circulator, that receives multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1310 onport1311, and outputs multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1310, on port1314 as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1315 toBOA1316.

BOA1316 may have a gain that is based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance,BOA1316 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, thegain BOA1316 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length of primary fiber1330 and/or the length of secondary fiber1331). Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1315 may be amplified byBOA1316, andBOA1316 may output multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1317 toport1318 ofWDM1319.WDM1319 outputs a multi-wavelength downstream optical data signal (e.g., multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1340) from port1320, which may be substantially the same as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1317. Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1340 may be input to variable optical amplifier (VOA)1321.

VOA1321 may be used to reduce the power levels of Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1340. The power reduction may done by absorption, reflection, diffusion, scattering, deflection, diffraction, and dispersion, of Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1340.VOA1321 typically have a working wavelength range in which they absorb all light energy equally. In someembodiments VOA1321 utilize a length of high-loss optical fiber, that operates upon its input optical signal power level in such a way that its output signal power level is less than the input level. For example, multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1340 may have an input power level toVOA1321 that may be greater than the output power level of multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1339.

The variability of the output power level ofVOA1321 may be achieved using a fiber coupler, where some of the power is not sent to the port that outputs, but to another port. Another possibility is to exploit variable coupling losses, which are influenced by variable positioning of a fiber end. For example, the transverse position of the output fiber or the width of an air gap between two fibers may be varied, obtaining a variable loss without a strong wavelength dependence. This principle may be used for single-mode fibers. VOA13211 may be based on some piece of doped fiber, exhibiting absorption within a certain wavelength range.

WDM1323 may multiplex multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1339 and one or more EPON, and/or GPON optical data signals. The EPON and/or GPON optical data signals may be received on a GPON/EPON connector (e.g., GPON/EPON1324) from PON port1302. The resulting multiplexed optical data signal may be referred to as egress optical data signal1335.

Egress optical data signal1335 may be output byWDM1323 andoptical switch1326 may switch egress optical data signal1335 ontoconnector1327 or connector1334 depending on the position ofswitch1326. In some embodiments,connector1327 may be a primary connector and connector1334 may be a secondary connector or a backup connector.Wavelength monitoring connector1328 may connectconnector1327 to a first port of wavelength-monitoring ports1344, andwavelength monitoring connector1333 may connect connector1334 to a second port of wavelength-monitoring ports1344. Wavelength-monitoring ports1344 may monitor the wavelengths in egress optical data signal1335 viaconnector1327 or connector1334 depending on the position ofswitch1326. Egress optical data signal1335 may exitheadend1301 viaconnector1327 connected to primary fiber1330, and may be received on a first connector in the field hub or outside plant. Egress optical data signal1335 may exitheadend1301 via connector1334 connected tosecondary fiber1331, and may be received on a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

The operation ofheadend1301 may be described by way of the processing of upstream optical data signals received atheadend1301 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal or a 10GEPN.XGPON may be an upstream optical data signal received on primary fiber1330 orsecondary fiber1331 depending on the position ofswitch1326.

Multi-wavelength ingress optical data signal1336 may traverseconnector1327 andswitch1326, before enteringWDM1323 viaport1337 ifswitch1326 is connected toconnector1327. Multi-wavelength ingress optical data signal1336 may traverse connector1334 andswitch1326, before enteringWDM1323 viaport1337 ifswitch1326 is connected toconnector1327.WDM1323 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from multi-wavelength ingress optical data signal1336.WDM1323 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON1324 to PON connector1302 viaport1325.WDM1323 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1341) out ofport1338 toOPA1342.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1341 may be received byOPA1342. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1341 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedOPA1342 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofBOA1316. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1341 may be amplified byOPA1342, andOPA1342 may output multi-wavelength upstream optical data signal1343 toWDM1313.

WDM1313 may receive the multi-wavelength upstream optical data signal1343 onport1312, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1309 toDCM1308.DCM1308 may perform one or more operations on one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1309 to compensate for any dispersion that may have been introduced by circuit components (e.g.,WDM1313,OPA1342, or WDM1323) or imperfections or issues with an optical fiber (e.g., primary fiber1330 or secondary fiber1331).DCM1308 may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306 toDWDM1305. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1309 are substantially the same as multi-wavelength upstream optical data signal1343.WDM1313 may function as a circulator when receiving multi-wavelength upstream optical data signal1343 onport1312. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306 may be received byDWDM1305.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1305 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1306 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1305 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1304. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1304 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1304 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 14 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.FIG. 14 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 14,headend1401 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM1405), a first WDM (e.g., WDM1410), a second WDM (e.g., WDM1418), a first DCM (e.g., DCM1413), asecond DCM1438, a GPON/EPON connector (e.g., GPON/EPON1420), a booster amplifier BOA (e.g., BOA1415), an optical pre-amplifier (OPA) (e.g., OPA1436), a first variable optical attenuator (VOA) (e.g., VOA1424), a second VOA (e.g., VOA1429), and anoptical switch1421 to feed a primary optical fiber (e.g., Primary Fiber1426) or secondary (backup) optical fiber (e.g., Secondary Fiber1427).DWDM1405 may be similar in functionality toDWDM106 andWDM1410 andWDM1418 may be similar in functionality toWDM108.DCM1413 andDCM1438 may be similar in functionality toDCM112. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

The EPON signals may operate with the same optical frequencies as GPON and time division multiple access (TDMA). The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions. EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON may not use a carrier sense multiple access (CSMA)/collision detection (CD) access method used in other versions of Ethernet. There is a 10-Gbit/s Ethernet version designated as 802.3av. The line rate may be 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1571 to 1591 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

In one aspect,headend1401 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbEE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1403) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1404). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1403 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1404 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1403 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190, and 20×coherent 100 GbE, 200 GbE, and/or 400GbE UP1404 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend1401 may be described by way of the processing of downstream optical data signals transmitted fromheadend1401 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1403 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1403 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1403 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1405 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1407) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1407 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1405 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1407, may be input toWDM1410.WDM1410 may be a three port circulator, that receives multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1407 onport1408, and outputs multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1407, onport1408 as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1412 on port1411 toDCM1413.

Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1412 may be input intoDCM1413 to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1412 may experience after being amplified by BOA1415 and multiplexed byWDM1428, with other optical data signals, that are downstream fromDCM1431. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend1401 over afiber connecting headend1401 to a field hub or outside plant. In some embodiments,DCM1413 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments,DCM1413 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically,DCM1413 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.DCM1413 may output a dispersion controlled version of 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1412 as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1414.

BOA1415 may have a gain that is based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, BOA1415 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain BOA1415 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1426 and/or the length of secondary fiber1427). Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1414 may be amplified by BOA1415, and BOA1415 may output multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS11416 toport1417 ofWDM1418.

WDM1418 may multiplex multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1416 and one or more EPON, and/or GPON optical data signals. The EPON and/or GPON optical data signals may be received on a GPON/EPON connector (e.g., GPON/EPON1420) fromPON port1402. The resulting multiplexed optical data signal may be referred to as egress optical data signal1432.

Egress optical data signal1432 may be output byWDM1418 andoptical switch1421 may switch egress optical data signal1432 ontoconnector1422 orconnector1431 depending on the position ofswitch1421. In some embodiments,connector1422 may be a primary connector andconnector1431 may be a secondary connector or a backup connector.Wavelength monitoring connector1423 may connectconnector1422 to a first port of wavelength-monitoring ports1440, and wavelength monitoring connector1430 may connectconnector1431 to a second port of wavelength-monitoring ports1440. Wavelength-monitoring ports1440 may monitor the wavelengths in egress optical data signal1432 viaconnector1422 orconnector1431 depending on the position ofswitch1421. Egress optical data signal1432 may exitheadend1401 either viaconnector1422 connected toprimary fiber1426, as egress optical data signal1441, or viaconnector1431 connected tosecondary fiber1427, as egress optical data signal1442, depending on the position ofswitch1421. Egress optical data signal1432 may be transmitted as, egress optical data signal1441, onprimary fiber1426 to a first connector in the field hub or outside plant. Egress optical data signal may be transmitted as, egress optical data signal1442, onsecondary fiber1427 to a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

Variable optical attenuator (VOA)1424 andVOA1429 may be used to reduce the power levels of egress optical data signal1432 or ingress optical data signal1433. The power reduction may done by absorption, reflection, diffusion, scattering, deflection, diffraction, and dispersion, of egress optical data signal1432 or ingress optical data signal1433. VOA1424 andVOA1429 typically have a working wavelength range in which they absorb all light energy equally. In some embodiments VOA1424 andVOA1429 utilize a length of high-loss optical fiber, that operates upon its input optical signal power level in such a way that its output signal power level is less than the input level. For example, egress optical data signal1432 may have an input power level to VOA1424 that may be greater than the output power level of egress optical data signal1441 as it is output from VOA1424. Similarly if egress optical data signal1432 is transmitted onconnector1431, egress optical data signal1432 may have an input power level toVOA1429 that may be greater than the output power level of egress optical data signal1442. In some embodiments, the output power level of egress optical data signal1441 may be greater than the output power level of egress optical data signal1442, and vice versa. The difference in output power levels between egress optical data signal1441 and egress optical data signal1442 may depend on the mode ofprimary fiber1426 andsecondary fiber1427. VOA1424 may have a similar functionality to that haveVOA1429.

The variability of the output power level of VOA1424 andVOA1429 may be achieved using a fiber coupler, where some of the power is not sent to the port that outputs, but to another port. Another possibility is to exploit variable coupling losses, which are influenced by variable positioning of a fiber end. For example, the transverse position of the output fiber or the width of an air gap between two fibers may be varied, obtaining a variable loss without a strong wavelength dependence. This principle may be used for single-mode fibers. VOA1424 andVOA1429 may be based on some piece of doped fiber, exhibiting absorption within a certain wavelength range.

The operation ofheadend1401 may be described by way of the processing of upstream optical data signals received atheadend1401 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber1426 orsecondary fiber1427 depending on the position ofswitch1421.

Because the multi-wavelength ingress optical data signal is routed toport1434 ofWDM1418, and is altered negligibly betweenconnector1422 andport1434 orconnector1432 andport1434, depending on the position ofswitch1421, the multi-wavelength ingress optical data signal may be substantially the same as ingress optical data signal1433. The multi-wavelength ingress optical data signal may traverseconnector1422 andswitch1421, before enteringWDM1418 viaport1434 ifswitch1421 is connected toconnector1422. The multi-wavelength ingress optical data signal may traverseconnector1431 andswitch1421, before enteringWDM1418 viaport1434 ifswitch1421 is connected toconnector1431.WDM1418 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from ingress optical data signal1433.WDM1418 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON11420 toPON connector1402 viaport1419.WDM1418 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1435) out ofport1421 toOPA1436.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1435 may be received byOPA1436. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1435 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedOPA1436 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that of BOA1415. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1435 may be amplified byOPA1436, andOPA1436 may output multi-wavelength upstream optical data signal1437 toDCM1438.

In some embodiments,DCM1438 may be configured to balance positive and/or negative dispersion that may be introduced to a SONET/SDH egress optical data signal that may enterheadend1401 from 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1404. The SONET/SDH egress optical data signal may be an upstream signal from a field hub or outside plant destined for a MTC. For example, a customer premise may be connected to the field hub or outside plant and may send one or more packets via a SONET/SDH network to the field hub or outside plant which may in turn transmit the one or more packets using 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals toheadend1401. The one or more packets may be destined for a company web server connected to the MTC via a backbone network. Becauseheadend1401 may be collocated in a STC that is connected to the MTC via an optical ring network, wherein the connection between the STC and MTC is an SONET/SDH optical network connection,DCM1438 may be configured to compensate for positive and/or negative dispersion on the SONET/SDH optical network connection. That isDCM1438 may be configured to reduce temporal broadening of the SONET/SDH egress optical data signal or temporal contraction of the SONET/SDH egress optical data signal.DCM1438 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1437 and my output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1439 toWDM1410.

WDM1410 may receive the multi-wavelength upstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1439 onport1409 ofWDM1410, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1206 toDWDM1405. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406 are substantially the same as multi-wavelength upstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1439.WDM1410 may function as a circulator when receiving multi-wavelength upstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1439 onport1409 and may output the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406 onport1408. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406 may be received byDWDM1405.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400Gb UP1406 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1405 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1406 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1405 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1404. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1404 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1404 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 15 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure.FIG. 15 shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 15,headend1501 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM1506), a first WDM (e.g., WDM1513), a second WDM (e.g., WDM1524), a GPON/EPON connector (e.g., GPON/EPON1528), a booster amplifier BOA (e.g., BOA1516), an optical pre-amplifier (OPA) (e.g., OPA1544), anoptical switch1530 to feed a primary optical fiber (e.g., Primary Fiber1550) or secondary (backup) optical fiber (e.g., Secondary Fiber1551).DWDM1506 may be similar in functionality toDWDM106 andWDM1513 andWDM1544 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in the MTC facility. A field hub or outside plant may house a multiplexer-demultiplexer (MDM) (e.g., MDM1591).

The EPON signals may operate with the same optical frequencies as GPON and time division multiple access (TDMA). The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions.

EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON may not use a carrier sense multiple access (CSMA)/collision detection (CD) access method used in other versions of Ethernet.

There is a 10-Gbit/s Ethernet version designated as 802.3ay. The line rate may be 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1571 to 1591 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

In one aspect,headend1501 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1503) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1504). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1503 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1504 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1503 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1504 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend1501 may be described by way of the processing of downstream optical data signals transmitted fromheadend1501 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or400GbEDS1503 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1503 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1503 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1506 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1508) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1508 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1506 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1508, may be input toWDM1513.WDM1513 may be a three port circulator, that receives multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1508 onport1509, and outputs multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1515, onport1514 as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1515 toBOA1516.

BOA1516 may have a gain that is based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance,BOA1516 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, thegain BOA1516 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1550 and/or the length of secondary fiber1551). Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1515 may be amplified byBOA1516, andBOA1516 may output multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1518 toport1520 of WDM1524. WDM1524 outputs an egress optical data signal fromport1541, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, EPON, and/or GPON optical data signals. The EPON and/or GPON optical data signals may be received on a GPON/EPON connector (e.g., GPON/EPON1528) fromPON port1502.

Egress optical data signal1539 may be output by WDM1524 andoptical switch1530 may switch egress optical data signal1539 ontoconnector1532 orconnector1538 depending on the position ofswitch1530. In some embodiments,connector1532 may be a primary connector andconnector1538 may be a secondary connector or a backup connector.Wavelength monitoring connector1534 may connectconnector1532 to a first port of wavelength-monitoring ports1548, and wavelength monitoring connector1537 may connectconnector1538 to a second port of wavelength-monitoring ports1548. Wavelength-monitoring ports1548 may monitor the wavelengths in egress optical data signal1539 viaconnector1532 orconnector1538 depending on the position ofswitch1530. Egress optical data signal1530 may exitheadend1501 either viaconnector1532 connected toprimary fiber1550, or viaconnector1538 connected tosecondary fiber1551, depending on the position ofswitch1530. Egress optical data signal1539 may be transmitted onprimary fiber1550 to an optical splitter (e.g., the optical splitter1593) inside of or collocated with a MDM (e.g., the MDM1591). Egress optical data signal1539 may be transmitted onsecondary fiber1551 to theoptical splitter1593.

Egress optical data signal1539 may be received atoptical splitter1593 as an ingress optical data signal.Optical splitter1593 may also be referred to as a beam splitter, and may comprise one or more quartz substrates of an integrated waveguide optical power distribution device.Optical splitter1593 may be a passive optical network device. It may be an optical fiber tandem deice comprising one or more input terminals and one or more output terminals.Optical splitter1539 may be Fused Biconical Taper (FBT) splitter or Planar Lightwave Circuit (PLC) splitter.Optical splitter1593 may be a balanced splitter whereinoptical splitter1593 comprises 2 input fibers and one or more output fibers over which the ingress optical data signal may be spread proportionally. In some embodiments, the ingress optical data signal may not be spread proportionally across the output fibers ofoptical splitter1593. In some embodiments,optical splitter1593 may comprise two input fibers and 2 output fibers. A first input fiber ofoptical splitter1593 may be connected toprimary fiber1550 and a second input fiber ofoptical splitter1593 may be connected tosecondary fiber1551.

A first output fiber ofoptical splitter1593 may be connected to a filter (e.g., C-band block1592) that filters out packets of light, in the ingress optical data signal, with wavelengths between 1530 nm and 1565 nm. This range of wavelengths may coincide with a C-band of wavelengths. In some other embodiments, the filter may filter out packets of light with wavelengths not inclusive of the wavelengths between 1260 nm and 1520 nm and not inclusive of wavelengths between 1570 nm and 1660 nm. The packets of light with wavelengths inclusive of the wavelengths between 1260 nm and 1520 nm and inclusive of wavelengths between 1570 nm and 1660 nm, may correspond to the wavelengths of the packets of light carrying the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1528. More specifically,optical splitter1593, may receive one or more downstream EPON and/or GPON optical data signals1560, in the ingress optical data signal, that corresponds to the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1528. In some embodiments, the one or more downstream EPON and/or GPON optical data signals1560 may have the same wavelength asGPON DS806.Optical splitter1593 may output the one or more downstream EPON and/or GPON optical data signals1560, received in the ingress optical data signal, to C-band block1592.

C-band block1592 may output one or more downstream EPON and/or GPONoptical data signals1597 corresponding to the one or more downstream EPON and/or GPONoptical data signals1560 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm. The C-band block1592 may transmit the one or more downstream EPON and/or GPONoptical data signals1597 to an express port (not shown inFIG. 15) collocated with, or attached toMDM1591. In some embodiments, the express port may be located within theMDM1591.

A second output fiber ofoptical splitter1593 may be connected to coupled optical power (COP)1594.COP1594 may be a PON device that monitors the coupled optical power betweenOptical Splitter1593 andDWDM1596. In some embodiments, the coupled optical power may be a percentage value. For instance, the coupled optical power may be 1%.Optical splitter1593, may receive one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, in the ingress optical data signal, that corresponds to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1508. In some embodiments, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals may have the same wavelength as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE808.Optical splitter1593 may output the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1563, received in the ingress optical data signal, toCOP1594.COP1594 may output a first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1563 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1595). The first percentage may be a percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1563 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1563 may be a monitoring signal used by a spectrum analyzer to measure optical power levels of a specific wavelength. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1563 may also be used by the spectrum analyzer to analyze certain characteristics of the wavelengths of the first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1563.COP1594 may output a second percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1565 toDWDM1596. Because the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1565 may be a multi-wavelength downstream opticaldata signal DWDM1596 may demultiplex the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1565 into individual optical data signals in accordance with the individual wavelengths of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1565. More specifically, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1565 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1596 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1598. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1598 may be in a RPD (not shown) and may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. In some embodiments, the RPD may be similar in functionality toRemote PHY Node207. The RPD may convert the SONET/SDH optical data signals into an electrical signal that may be transmitted over one or more coaxial cables.MDM1591 may be similar in functionality toMDM208 and may be connected to the RPD in a way similar to the connection betweenMDM208 andRemote PHY Node207.

The operation ofMDM1591 may be further described by way of the processing of an upstream optical data signal transmitted toheadend1501. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1599 may receive a SONET/SDH optical data signal and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1599 may receive the SONET/SDH optical data signal from the RPD. The RPD may also convert one or more electrical signals into the SONET/SDH optical data signal.

More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1599 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1599 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1596 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength upstream optical data signal (e.g., multi-wavelength upstream optical data signal1564) comprising the twenty corresponding second optical data signals. The multi-wavelength upstream optical data signal1564 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1596 may multiplex the twenty corresponding second optical data signals onto thefiber connecting DWDM1596 andCOP1594, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength upstream optical data signal1564, may be input toCOP1594.COP1594 may output a first percentage of the multi-wavelength upstream optical data signal1564 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1695). The first percentage may be a percentage of the multi-wavelength upstream optical data signal1564 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstreamtest ports COP1594 may output a second percentage of the multi-wavelength upstream optical data signal1564 tooptical splitter1593 as the multi-wavelength upstream optical data signal1562.

C-band block1592 may receive one or more upstream EPON and/or GPONoptical data signals1566 from an express port (not shown inFIG. 15) collocated with, or attached toMDM1591. In some embodiments, the express port may be located within theMDM1591. C-band block1592 may filter out packets of light, in the one or more upstream EPON and/or GPON optical data signals1566, with wavelengths between 1530 nm and 1565 nm. Thus C-band block1592 may output one or more upstream EPON and/or GPONoptical data signals1561 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm.

Optical splitter1593 may receive one or more upstream EPON and/or GPON optical data signals1561, and may also receive the multi-wavelength upstream optical data signal1562, and may multiplex the multi-wavelength one or more upstream EPON and/or GPONoptical data signals1561 with the multi-wavelength upstream optical data signal1562.Optical splitter1593 outputs an egress optical data signal, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON/EPON optical data signals corresponding to the multiplexed multi-wavelength one or more upstream EPON and/or GPONoptical data signals1561 and multi-wavelength upstream optical data signal1562.Optical splitter1593 may output the egress optical data signal ontoprimary fiber1550 connecting theoptical splitter1593 toport1536.Optical splitter1593 may also output the egress optical data signal ontosecondary fiber1551 connecting theoptical splitter1593 toport1546.

The operation ofheadend1501 may be described by way of the processing of upstream optical data signals received atheadend1501 fromMDM1591. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber1550 orsecondary fiber1551 depending on the position ofswitch1530. The upstream optical data signal may be substantially the same as the egress optical data signal.

The multi-wavelength ingress optical data signal1540 may traverseconnector1532 andswitch1530, before entering WDM1524 viaport1541 ifswitch1530 is connected toconnector1532. The multi-wavelength ingress optical data signal may traverseconnector1538 andswitch1530, before entering WDM1524 viaport1541 ifswitch1530 is connected toconnector1538. WDM1524 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from ingress optical data signal1540. WDM1524 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON1528 toPON connector1502 viaport1522. WDM1524 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1542) out ofport1526 toOPA1544.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1542 may be received byOPA1544. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1542 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedOPA1544 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofBOA1516. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1542 may be amplified byOPA1544, andOPA1544 may output multi-wavelength upstream optical data signal1512 toWDM1513.

WDM1513 may receive the multi-wavelength upstream optical data signal1512 onport1510 ofWDM1513, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 toDWDM1513. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 are substantially the same as multi-wavelength upstream optical data signal1512.WDM1513 may function as a circulator when receiving multi-wavelength upstream optical data signal1512 onport1510 and outputting the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 onport1509. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 may be received byDWDM1506.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1506 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1511 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1506 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1504. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1504 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1504 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 16 depicts a process of transmitting optical signals with the OCML headend, in accordance with the disclosure. As shown inFIG. 16,headend1601 is a smart integrated OCML headend, which is a circuit, comprising one or more EDFAs (e.g., booster optical amplifier (BOA)1616 and optical pre-amplifier (OPA)1633), a DWDM (e.g., DWDM1605), one or more WDMs (e.g.,WDM1610 and1619), one or more DCMs (e.g.,DCM1615 and1635), and anoptical switch1625 to feed a primary optical fiber (e.g., Primary Fiber1637) or secondary (backup) optical fiber (e.g., Secondary Fiber1638). The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/XGPON/10GEPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g., MDM1691).

In one aspect,headend1601 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1603) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1604). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1603 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1604 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths.Headend1601 may a connector (e.g., PON1602), that may transmit and receive GPON and/or EPON signals on a GPON/EPON connector (e.g., GPON/EPON1618).Headend1601 may also comprise two wavelength-monitoring ports (e.g., wavelength-monitoring ports1636), a primary optical fiber (e.g., primary optical fiber1637) and a secondary optical fiber (e.g., secondary optical fiber1638) that transmit and receive a plurality of multi-wavelength 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON optical signals. Primaryoptical fiber1637 and secondaryoptical fiber1638 may transmit a first plurality of multi-wavelength 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or XGPON/10GEPON optical signals fromheadend1601 to a multiplexer-demultiplexer (MDM) in a outside plant (e.g., MDM1691), and may receive a second plurality of multi-wavelength 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON, and/or EPON optical signals fromMDM1691.

In one aspect,headend1601 can transmit and receive up to twenty bi-directional 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, but the actual number of optical data signals may depend on operational needs. That is,headend1601 can transport more or less than twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream optical signals, or more or less than twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream optical data signals, based on the needs of customers' networks (e.g.,Remote PHY Network216,Enterprise Network218, Millimeter Wave Network214). These customer networks may be connected toheadend1601 through an optical ring network (e.g., metro access optical ring network206).

The operation ofheadend1601 may be described by way of the processing of downstream optical data signals transmitted fromheadend1601 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1603 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1603 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1603 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1605 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1606) comprising the twenty corresponding second optical data signals onto a fiber. More specifically,DWDM1605 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength downstream optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606, may be input to a WDM (e.g. WDM1610).WDM1610 may be a three port wave division multiplexer (WDM), or a three port circulator, that receives 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606 onport1608 and outputs 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606 onport1611 as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1614. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1614 may be substantially the same as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606 becauseWDM1610 may function as a circulator when 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606 is input onport1608.

10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1614 may be input into a DCM (e.g., DCM1615) to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1614 may experience after being amplified by an EDFA and multiplexed by a WDM, with other optical data signals, that are downstream from the DCM. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend1601 over afiber connecting headend1601 to a field hub or outsideplant containing MDM1691. In some embodiments,DCM1615 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments,DCM1615 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically,DCM1615 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.

DCM1615 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1614 and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1653 to an EDFA (e.g., BOA1616). A gain ofBOA1616 may be based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance, the gain ofBOA1616 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain ofBOA1616 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1637 and/or the length of secondary fiber1638). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1653 may be amplified byBOA1616, andBOA1616 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1620 toport1617 ofWDM1619.

WDM1619 may be a WDM that may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1620 with one or more PON signals received on (GPON/EPON1618). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1620 may be a multi-wavelength optical data signal, wherein the wavelengths comprise the same wavelengths as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1606. In some embodiments, the wavelengths of the multi-wavelength optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1620 may be within the conventional c band of wavelengths, which may include wavelengths within the 1520 nm-1565 nm range. GPON184 may be a fiber carrying a GPON optical data signal with a wavelength of 1490 nm. The GPON signal may be input toWDM1619 onport1671.WDM1619 outputs an egress optical data signal fromport1622, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, EPON, and GPON optical data signals.WDM1619 may multiplex 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1620, EPON optical data signals, and GPON optical data signals thesame way DWDM1605 multiplexes optical data signals. The egress optical data signal (e.g., egress optical data signal1624) may be output onport1622 ofWDM1619 andoptical switch1625 may switch egress optical data signal1624 out ofconnector1626 orconnector1631. In some embodiments,connector1626 may be a primary connector andconnector1631 may be a secondary connector or a backup connector.Wavelength monitoring connector1627 may connectconnector1626 to a first port of wavelength-monitoring ports1636, andwavelength monitoring connector1629 may connectconnector1631 to a second port of wavelength-monitoring ports1636. Wavelength-monitoring ports1636 may monitor the wavelengths in egress optical data signal1624 viaconnector1626 orconnector1631 depending on the position ofswitch1625. Egress optical data signal1624 may exitheadend1601 either viaconnector1626 connected toprimary fiber1637 or viaconnector1631 connected tosecondary fiber1638 depending on the position ofswitch1625. Egress optical data signal1624 may be transmitted onprimary fiber1637 to a first connector an optical splitter (e.g., the optical splitter1693) inside of or collocated with a MDM (e.g., the MDM1691). Egress optical data signal1539 may be transmitted onsecondary fiber1638 to a second connector inoptical splitter1693.

Egress optical data signal1624 may be received atoptical splitter1693 as an ingress optical data signal.Optical splitter1693 may also be referred to as a beam splitter, and may comprise one or more quartz substrates of an integrated waveguide optical power distribution device.Optical splitter1693 may be a passive optical network device. It may be an optical fiber tandem deice comprising one or more input terminals and one or more output terminals. Optical splitter1639 may be Fused Biconical Taper (FBT) splitter or Planar Lightwave Circuit (PLC) splitter.Optical splitter1693 may be a balanced splitter whereinoptical splitter1693 comprises 2 input fibers and one or more output fibers over which the ingress optical data signal may be spread proportionally. In some embodiments, the ingress optical data signal may not be spread proportionally across the output fibers ofoptical splitter1693. In some embodiments,optical splitter1693 may comprise two input fibers and 2 output fibers. A first input fiber ofoptical splitter1693 may be connected toprimary fiber1637 and a second input fiber ofoptical splitter1593 may be connected tosecondary fiber1638.

A first output fiber ofoptical splitter1693 may be connected to a filter (e.g., C-band block1692) that filters out packets of light, in the ingress optical data signal, with wavelengths between 1530 nm and 1565 nm. This range of wavelengths may coincide with a C-band of wavelengths. In some other embodiments, the filter may filter out packets of light with wavelengths not inclusive of the wavelengths between 1260 nm and 1520 nm and not inclusive of wavelengths between 1570 nm and 1660 nm. The packets of light with wavelengths inclusive of the wavelengths between 1260 nm and 1520 nm and inclusive of wavelengths between 1570 nm and 1660 nm, may correspond to the wavelengths of the packets of light carrying the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1618. More specifically,optical splitter1693, may receive one or more downstream EPON and/or GPON optical data signals1660, in the ingress optical data signal, that corresponds to the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1618. In some embodiments, the one or more downstream EPON and/or GPON optical data signals1660 may have the same wavelength asGPON DS806.Optical splitter1693 may output the one or more downstream EPON and/or GPON optical data signals1660, received in the ingress optical data signal, to C-band block1692.

C-band block1692 may output one or more downstream EPON and/or GPONoptical data signals1697 corresponding to the one or more downstream EPON and/or GPONoptical data signals1660 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm. The C-band block1692 may transmit the one or more downstream EPON and/or GPONoptical data signals1697 to an express port (not shown inFIG. 16) collocated with, or attached toMDM1691. In some embodiments, the express port may be located within theMDM1691.

A second output fiber ofoptical splitter1693 may be connected to coupled optical power (COP)1694.COP1694 may be a PON device that monitors the coupled optical power betweenOptical Splitter1693 andDWDM1696. In some embodiments, the coupled optical power may be a percentage value. For instance, the coupled optical power may be 1%.Optical splitter1693, may receive one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, in the ingress optical data signal, that corresponds to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1608. In some embodiments, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals may have the same wavelength as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE808.Optical splitter1693 may output the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1663, received in the ingress optical data signal, toCOP1694.COP1694 may output a first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1663 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1695). The first percentage may be a percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1663 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1663 may be a monitoring signal used by a spectrum analyzer to measure optical power levels of a specific wavelength. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1663 may also be used by the spectrum analyzer to analyze certain characteristics of the wavelengths of the first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1663.COP1694 may output a second percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1665 toDWDM1696.

Because the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1665 may be a multi-wavelength downstream opticaldata signal DWDM1696 may demultiplex the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1665 into individual optical data signals in accordance with the individual wavelengths of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1665. More specifically, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1665 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1696 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1698. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1698 may be in a RPD (not shown) and may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. In some embodiments, the RPD may be similar in functionality toRemote PHY Node207. The RPD may convert the SONET/SDH optical data signals into an electrical signal that may be transmitted over one or more coaxial cables.MDM1691 may be similar in functionality toMDM208 and may be connected to the RPD in a way similar to the connection betweenMDM208 andRemote PHY Node207.

The operation ofMDM1691 may be further described by way of the processing of an upstream optical data signal transmitted toheadend1601. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1699 may receive a SONET/SDH optical data signal and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1699 may receive the SONET/SDH optical data signal from the RPD. The RPD may also convert one or more electrical signals into the SONET/SDH optical data signal.

More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1699 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1699 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1696 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength upstream optical data signal (e.g., multi-wavelength upstream optical data signal1664) comprising the twenty corresponding second optical data signals. The multi-wavelength upstream optical data signal1664 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1696 may multiplex the twenty corresponding second optical data signals onto thefiber connecting DWDM1696 andCOP1694, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength upstream optical data signal1664, may be input toCOP1694.COP1694 may output a first percentage of the multi-wavelength upstream optical data signal1664 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1695). The first percentage may be a percentage of the multi-wavelength upstream optical data signal1664 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports. The first percentage of the multi-wavelength upstream optical data signal1664 may be a monitoring signal used by a spectrum analyzer to measure optical power levels of a specific wavelength in the multi-wavelength upstream optical data signal1664. The first percentage of the multi-wavelength upstream optical data signal1664 may also be used by the spectrum analyzer to analyze certain characteristics of the wavelengths of the first percentage of the multi-wavelength upstream optical data signal1664.COP1694 may output a second percentage of the multi-wavelength upstream optical data signal1664 tooptical splitter1693 as the multi-wavelength upstream optical data signal1662.

C-band block1692 may receive one or more upstream EPON and/or GPONoptical data signals1666 from an express port (not shown inFIG. 16) collocated with, or attached toMDM1691. In some embodiments, the express port may be located within theMDM1691. C-band block1692 may filter out packets of light, in the one or more upstream EPON and/or GPON optical data signals1666, with wavelengths between 1530 nm and 1565 nm. Thus C-band block1692 may output one or more upstream EPON and/or GPONoptical data signals1661 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm.

Optical splitter1693 may receive one or more upstream EPON and/or GPON optical data signals1661, and may also receive the multi-wavelength upstream optical data signal1662, and may multiplex the multi-wavelength one or more upstream EPON and/or GPONoptical data signals1661 with the multi-wavelength upstream optical data signal1662.Optical splitter1693 outputs an egress optical data signal, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON/EPON optical data signals corresponding to the multiplexed multi-wavelength one or more upstream EPON and/or GPONoptical data signals1661 and multi-wavelength upstream optical data signal1662.Optical splitter1693 may output the egress optical data signal ontoprimary fiber1637 connecting theoptical splitter1693 toport1628.Optical splitter1693 may also output the egress optical data signal ontosecondary fiber1638 connecting theoptical splitter1693 toport1630.

The operation ofheadend1601 may be described by way of the processing of upstream optical data signals received atheadend1601 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal, may be an upstream optical data signal received onprimary fiber1637 orsecondary fiber1638 depending on the position ofswitch1625. The upstream optical data signal may be substantially the same as the egress optical data signal.

Because the multi-wavelength ingress optical data signal is routed toport1622 ofWDM1619, and is altered negligibly betweenconnector1626 andport1622 orconnector1631 andport1622, depending on the position ofswitch1625, the multi-wavelength ingress optical data signal may be substantially the same as ingress optical data signal1623. The multi-wavelength ingress optical data signal may traverse1626 andswitch1625, before enteringWDM1619 viaport1622 ifswitch1625 is connected toconnector1626. The multi-wavelength ingress optical data signal may traverseconnector1631switch1625, before enteringWDM1619 viaport1622 ifswitch1625 is connected toconnector1631.WDM1619 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from ingress optical data signal1623.WDM1619 may transmit the one or more EPON optical data signals alongGPON1618 toPON connector1602.WDM1619 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1632) out ofport1621 toOPA1633.

A gain ofOPA1633 may be based at least in part on a distance that the SONET/SDH egress optical data signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment on the SONET/SDH optical network connection. For instance, the gain ofOPA1633 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, the gain ofOPA1633 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length of the fiber of the SONET/SDH optical network connection). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1632 may be amplified byOPA1633, andOPA1633 may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1634 toDCM1635.

In some embodiments,DCM1635 may be configured to balance positive and/or negative dispersion that may be introduced to a SONET/SDH egress optical data signal that may exitheadend1601 from 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1604. The SONET/SDH egress optical data signal may be an upstream signal from a field hub or outside plant destined for a MTC. For example, a customer premise may be connected to the field hub or outside plant and may send one or more packets via a SONET/SDH network to the field hub or outside plant which may in turn transmit the one or more packets using 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals toheadend1601. The one or more packets may be destined for a company web server connected to the MTC via a backbone network. Becauseheadend1601 may be collocated in a STC that is connected to the MTC via an optical ring network, wherein the connection between the STC and MTC is an SONET/SDH optical network connection,DCM1635 may be configured to compensate for positive and/or negative dispersion on the SONET/SDH optical network connection. That isDCM1635 may be configured to reduce temporal broadening of the SONET/SDH ingress optical data signal or temporal contraction of the SONET/SDH ingress optical data signal.DCM1635 may input 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1634 and my output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1613 toWDM1610.

WDM1610 may receive 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1613 onport1612, and may output 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1613 onport1608 as a multi-wavelength upstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1609). 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1609 is substantially the same as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1613 is input toport1612. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1609 may be received byDWDM1605, andDWDM1605 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals from 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1609. Because 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1609 is a dispersion compensated amplified version of the multi-wavelength ingress optical data signal,DWDM1605 may demultiplex the one or more optical data signals into individual optical data signals in accordance with the individual wavelengths of any 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals in the multi-wavelength ingress optical data signal. More specifically, 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1609 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1605 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1604. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1604 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1604 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIGS. 17A and 17B depicts an access network diagram of an OCML headend comprising WDMs, a DWDM, optical amplifiers, and dispersion control modules (DCMs), in accordance with the disclosure.FIG. 17A shows a schematic of an OCML headend according to at least one embodiment of the disclosure. As shown inFIG. 17A,headend1701 is a smart integrated OCML headend, which is a circuit, comprising a DWDM (e.g., DWDM1705), a first WDM (e.g., WDM1713), a second WDM (e.g., WDM1719), a third WDM (e.g., WDM1723), a GPON/EPON connector (e.g., GPON/EPON1724), a booster amplifier BOA (e.g., BOA1716), an optical pre-amplifier (OPA) (e.g., OPA1742), a variable optical attenuator (VOA) (e.g., VOA1721), anoptical switch1726 to feed a primary optical fiber (e.g., Primary Fiber1730) or secondary (backup) optical fiber (e.g., Secondary Fiber1731), and a dispersion control module (DCM) (e.g., DCM1708).DWDM1705 may be similar in functionality toDWDM106 and WDM1713,WDM1719, andWDM1723 may be similar in functionality toWDM108. The disclosure provides a method of transporting multiple 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE and GPON/EPON signals on the same optical fiber over extended links of up to 60 kms without a cable company having to put optical amplifiers between the cable's Master Terminal Center (MTC) facility and a field hub or outside plant. The MTC facility may be an inside plant facility where a cable company acquires and combines services to be offered to customers. The MTC facility provides these combined services to customers, by transmitting and receiving optical signals over a plurality of optical fibers to a field hub or outside plant which connects the plurality of optical fibers to a customer's premise. The OCML headend may be located in a secondary terminal center (STC) that connects the MTC facility to a field hub or outside plant housing a multiplexer-demultiplexer (MDM) (e.g.,MDM208 inFIG. 2).

The EPON signals may operate with the same optical frequencies as GPON and time division multiple access (TDMA). The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions. EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON may not use a carrier sense multiple access (CSMA)/collision detection (CD) access method used in other versions of Ethernet. There is a 10-Gbit/s Ethernet version designated as 802.3ay. The line rate may be 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1575 to 1591 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system.

In one aspect,headend1701 may comprise twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE downstream (DS) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1703) and twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream (UP) transponders (e.g., 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP1704). 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1703 may transmit downstream data over twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may receive upstream data over 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE wavelengths. 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1703 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE190, and 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may comprise the same elements and perform the same operations as 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP188.

The operation ofheadend1701 may be described by way of the processing of downstream optical data signals transmitted fromheadend1701 to a field hub or outside plant, and the processing of upstream optical data signals received from the field hub or outside plant. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1703 may receive a SONET/SDH optical data signal from a MTC and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1703 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1703 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1705 may receive the twenty corresponding second optical data signals as an input and output a multi-wavelength downstream optical data signal (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1707) comprising the twenty corresponding second optical data signals onto a fiber. The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1707 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1705 may multiplex the twenty corresponding second optical data signals onto the fiber, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1707, may be input toDCM1708. 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1707 may be input intoDCM1708 to compensate for dispersion that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1707 may experience after being amplified byBOA1716 and multiplexed byWDM1723, with other optical data signals, that are downstream from the DCM. The amplified and multiplexed optical data signal may be referred to as an egress optical data signal, as it is the optical data signal that may be transmitted out ofheadend1701 over afiber connecting headend1701 to a field hub or outside plant. In some embodiments,DCM1708 may be configured to balance positive and/or negative dispersion that may be introduced to the egress optical data signal by the fiber. In some embodiments,DCM1708 may be configured to compensate for positive (temporal broadening of the egress optical data signal) and/or negative (temporal contraction of the egress optical data signal) dispersion introduced by fiber that is 80 km or greater in length, to reduce the sensitivity or OSNR levels of a transceiver in a DWDM located at a field hub or outside plant. More specifically,DCM1708 may be configured to reduce the sensitivity or OSNR level requirement in a photodetector or fiber-optic sensor in the transceiver, which may drastically reduce the cost of the transceivers used in the DWDM located at the field hub or outside plant.DCM1708 may output a dispersion controlled version of 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1707 as coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1710.

WDM1713 may be a three port circulator, that receives multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1710 onport1711, and outputs multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1710, onport1714 as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1715 toBOA1716. In some embodiments,Headend1701 may not includeDCM1708.

BOA1716 may have a gain that is based at least in part on a distance that a downstream signal has to travel. For example, the gain may be a function of a fiber attenuation coefficient α, which is a measure of the intensity of the attenuation of a beam of light as it traverses a length of an optical fiber segment. The unit of measurement of the fiber attenuation coefficient is decibels (dB) per km (dB/km). For instance,BOA1716 may be adjusted based at least in part on the attenuation coefficient and length of fiber that the egress optical data signal will travel. More specifically, thegain BOA1716 may be G=e^(2αL), where a is the fiber attenuation coefficient, as explained above, and L is the length of the fiber (e.g., the length ofprimary fiber1730 and/or the length of secondary fiber1731). Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1715 may be amplified byBOA1716, andBOA1716 may output multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1717 toport1718 ofWDM1719.WDM1719 outputs a multi-wavelength downstream optical data signal (e.g., multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1740) fromport1720, which may be substantially the same as multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1717. Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1740 may be input to variable optical amplifier (VOA)1721.

VOA1721 may be used to reduce the power levels of Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1740. The power reduction may done by absorption, reflection, diffusion, scattering, deflection, diffraction, and dispersion, of Multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1740.VOA1721 typically have a working wavelength range in which they absorb all light energy equally. In someembodiments VOA1721 utilize a length of high-loss optical fiber, that operates upon its input optical signal power level in such a way that its output signal power level is less than the input level. For example, multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1740 may have an input power level toVOA1721 that may be greater than the output power level of multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1739.

The variability of the output power level ofVOA1721 may be achieved using a fiber coupler, where some of the power is not sent to the port that outputs, but to another port. Another possibility is to exploit variable coupling losses, which are influenced by variable positioning of a fiber end. For example, the transverse position of the output fiber or the width of an air gap between two fibers may be varied, obtaining a variable loss without a strong wavelength dependence. This principle may be used for single-mode fibers. VOA17211 may be based on some piece of doped fiber, exhibiting absorption within a certain wavelength range.

WDM1723 may multiplex multi-wavelength downstream optical data signal 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1739 and one or more EPON, and/or GPON optical data signals. The EPON and/or GPON optical data signals may be received on a GPON/EPON connector (e.g., GPON/EPON1724) fromPON port1702. The resulting multiplexed optical data signal may be referred to as egress optical data signal1735.

FIG. 17B depicts an access network diagram of a multiplexer-demultiplexer (MDM), in accordance with the disclosure. Egress optical data signal1735 may be output byWDM1723 andoptical switch1726 may switch egress optical data signal1735 onto connector1727 orconnector1734 depending on the position ofswitch1726. In some embodiments, connector1727 may be a primary connector andconnector1734 may be a secondary connector or a backup connector.Wavelength monitoring connector1728 may connect connector1727 to a first port of wavelength-monitoring ports1744, andwavelength monitoring connector1733 may connectconnector1734 to a second port of wavelength-monitoring ports1744. Wavelength-monitoring ports1744 may monitor the wavelengths in egress optical data signal1735 via connector1727 orconnector1734 depending on the position ofswitch1726. Egress optical data signal1735 may exitheadend1701 via connector1727 connected toprimary fiber1730, and may be received on a first connector in the field hub or outside plant. Egress optical data signal1735 may exitheadend1701 viaconnector1734 connected tosecondary fiber1731, and may be received on a second connector in the field hub or outside plant. The field hub or outside plant may include a MDM with the first connector and the second connector.

Egress optical data signal1735 may be received atoptical splitter1793 as an ingress optical data signal.Optical splitter1793 may also be referred to as a beam splitter, and may comprise one or more quartz substrates of an integrated waveguide optical power distribution device.Optical splitter1793 may be a passive optical network device. It may be an optical fiber tandem deice comprising one or more input terminals and one or more output terminals.Optical splitter1739 may be Fused Biconical Taper (FBT) splitter or Planar Lightwave Circuit (PLC) splitter.Optical splitter1793 may be a balanced splitter whereinoptical splitter1793 comprises 2 input fibers and one or more output fibers over which the ingress optical data signal may be spread proportionally. In some embodiments, the ingress optical data signal may not be spread proportionally across the output fibers ofoptical splitter1793. In some embodiments,optical splitter1793 may comprise two input fibers and 2 output fibers. A first input fiber ofoptical splitter1793 may be connected toprimary fiber1737 and a second input fiber ofoptical splitter1793 may be connected tosecondary fiber1738.

A first output fiber ofoptical splitter1793 may be connected to a filter (e.g., C-band block1792) that filters out packets of light, in the ingress optical data signal, with wavelengths between 1530 nm and 1565 nm. This range of wavelengths may coincide with a C-band of wavelengths. In some other embodiments, the filter may filter out packets of light with wavelengths not inclusive of the wavelengths between 1260 nm and 1520 nm and not inclusive of wavelengths between 1570 nm and 1660 nm. The packets of light with wavelengths inclusive of the wavelengths between 1260 nm and 1520 nm and inclusive of wavelengths between 1570 nm and 1660 nm, may correspond to the wavelengths of the packets of light carrying the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1724. More specifically,optical splitter1793, may receive one or more downstream EPON and/or GPON optical data signals1760, in the ingress optical data signal, that corresponds to the one or more EPON and/or GPON optical data signals transmitted along GPON/EPON1724. In some embodiments, the one or more downstream EPON and/or GPON optical data signals1760 may have the same wavelength asGPON DS806.Optical splitter1793 may output the one or more downstream EPON and/or GPON optical data signals1760, received in the ingress optical data signal, to C-band block1792.

C-band block1792 may output one or more downstream EPON and/or GPONoptical data signals1797 corresponding to the one or more downstream EPON and/or GPONoptical data signals1760 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm. The C-band block1792 may transmit the one or more downstream EPON and/or GPONoptical data signals1797 to an express port (not shown inFIG. 17) collocated with, or attached toMDM1791. In some embodiments, the express port may be located within theMDM1791.

A second output fiber ofoptical splitter1793 may be connected toCOP1794.COP1794 may be a PON device that monitors the coupled optical power betweenOptical Splitter1793 andDWDM1796. In some embodiments, the coupled optical power may be a percentage value. For instance, the coupled optical power may be 1%.Optical splitter1793, may receive one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, in the ingress optical data signal, that corresponds to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE DS1708. In some embodiments, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals may have the same wavelength as 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE808.Optical splitter1793 may output the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1763, received in the ingress optical data signal, toCOP1794.COP1794 may output a first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1763 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1795). The first percentage may be a percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1763 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1763 may be a monitoring signal used by a spectrum analyzer to measure optical power levels of a specific wavelength. The first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1763 may also be used by the spectrum analyzer to analyze certain characteristics of the wavelengths of the first percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1763.COP1794 may output a second percentage of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1765 toDWDM1796.

Because the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1765 may be a multi-wavelength downstream opticaldata signal DWDM1796 may demultiplex the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1765 into individual optical data signals in accordance with the individual wavelengths of the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals1765. More specifically, the one or more downstream 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbEoptical data signals1765 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1796 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1798. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE DS1798 may be in a RPD (not shown) and may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. In some embodiments, the RPD may be similar in functionality toRemote PHY Node207. The RPD may convert the SONET/SDH optical data signals into an electrical signal that may be transmitted over one or more coaxial cables.MDM1791 may be similar in functionality toMDM208 and may be connected to the RPD in a way similar to the connection betweenMDM208 andRemote PHY Node207.

The operation ofMDM1791 may be further described by way of the processing of an upstream optical data signal transmitted toheadend1701. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1799 may receive a SONET/SDH optical data signal and each of the transponders may convert the SONET/SDH optical data signal into an electrical signal. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1799 may receive the SONET/SDH optical data signal from the RPD. The RPD may also convert one or more electrical signals into the SONET/SDH optical data signal.

More specifically, a first transceiver in the transponder may convert the SONET/SDH optical data signal into an electrical signal. A second transceiver may then convert the electrical signal into a second optical data signal, wherein the second optical data signal comprises one or more packets of light each of which may have a distinct wavelength. Because the one or more packets of light each have a distinct wavelength, the second optical data signal may be said to have this distinct wavelength. Thus, the twenty transponders in 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1799 may each receive a SONET/SDH optical data signal, and each of the twenty transponders may convert the received SONET/SDH optical data signal into a corresponding second optical data signal, wherein each of the corresponding second optical data signals has a unique wavelength. That is, the wavelength of each of the corresponding second optical data signals is distinguishable from the wavelength of any of the other corresponding second optical data signals. Thus 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1799 may generate twenty corresponding second optical data signals each of which has a unique wavelength.

DWDM1796 may receive twenty corresponding second optical data signals as an input and output a multi-wavelength upstream optical data signal (e.g., multi-wavelength upstream optical data signal1764) comprising the twenty corresponding second optical data signals. The multi-wavelength upstream optical data signal1764 may be a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal. More specifically,DWDM1796 may multiplex the twenty corresponding second optical data signals onto thefiber connecting DWDM1796 andCOP1794, wherein the twenty multiplexed corresponding second optical data signals compose the multi-wavelength downstream optical data signal. The multi-wavelength optical data signal may have a wavelength comprising the twenty wavelengths of the twenty corresponding second optical data signals.

The multi-wavelength upstream optical data signal1764, may be input toCOP1794.COP1794 may output a first percentage of the multi-wavelength upstream optical data signal1664 to 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports (e.g., 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE UP & DS Test Ports1795). The first percentage may be a percentage of the multi-wavelength upstream optical data signal1764 tested by the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE upstream and downstream test ports. The first percentage of the multi-wavelength upstream optical data signal1764 may be a monitoring signal used by a spectrum analyzer to measure optical power levels of a specific wavelength in the multi-wavelength upstream optical data signal1764. The first percentage of the multi-wavelength upstream optical data signal1764 may also be used by the spectrum analyzer to analyze certain characteristics of the wavelengths of the first percentage of the multi-wavelength upstream optical data signal1764.COP1794 may output a second percentage of the multi-wavelength upstream optical data signal1764 tooptical splitter1793 as the multi-wavelength upstream optical data signal1762.

C-band block1792 may receive one or more upstream EPON and/or GPONoptical data signals1766 from an express port (not shown inFIG. 17) collocated with, or attached toMDM1791. In some embodiments, the express port may be located within theMDM1791. C-band block1792 may filter out packets of light, in the one or more upstream EPON and/or GPON optical data signals1766, with wavelengths between 1530 nm and 1565 nm. Thus C-band block1792 may output one or more upstream EPON and/or GPONoptical data signals1761 with wavelengths between 1260 nm and 1520 nm and wavelengths between 1570 nm and 1660 nm.

Optical splitter1793 may receive one or more upstream EPON and/or GPON optical data signals1761, and may also receive the multi-wavelength upstream optical data signal1762, and may multiplex the multi-wavelength one or more upstream EPON and/or GPONoptical data signals1761 with the multi-wavelength upstream optical data signal1762.Optical splitter1793 outputs an egress optical data signal, which may be a multi-wavelength optical data signal comprising 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE, GPON/EPON optical data signals corresponding to the multiplexed multi-wavelength one or more upstream EPON and/or GPONoptical data signals1761 and multi-wavelength upstream optical data signal1762.Optical splitter1793 may output the egress optical data signal ontoprimary fiber1730 connecting theoptical splitter1793 toport1729.Optical splitter1793 may also output the egress optical data signal ontosecondary fiber1731 connecting theoptical splitter1793 toport1731.

The operation ofheadend1701 may be described by way of the processing of upstream optical data signals received atheadend1701 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal or a 10GEPN.XGPON may be an upstream optical data signal received onprimary fiber1730 orsecondary fiber1731 depending on the position ofswitch1726. The upstream optical data signal may be substantially the same as the egress optical data signal.

Multi-wavelength ingress optical data signal1736 may traverse connector1727 andswitch1726, before enteringWDM1723 viaport1737 ifswitch1726 is connected to connector1727. Multi-wavelength ingress optical data signal1736 may traverseconnector1734 andswitch1726, before enteringWDM1723 viaport1737 ifswitch1726 is connected to connector1727.WDM1723 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from multi-wavelength ingress optical data signal1736.WDM1723 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON1724 toPON connector1702 viaport1725.WDM1723 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1741) out ofport1738 toOPA1742.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may be received byOPA1742. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedOPA1742 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofBOA1716. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may be amplified byOPA1742, andOPA1742 may output multi-wavelength upstream optical data signal1743 to WDM1713.

WDM1713 may receive the multi-wavelength upstream optical data signal1743 onport1712, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 toDCM1708.DCM1708 may perform one or more operations on one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 to compensate for any dispersion that may have been introduced by circuit components (e.g., WDM1713,OPA1742, or WDM1723) or imperfections or issues with an optical fiber (e.g.,primary fiber1730 or secondary fiber1731).DCM1708 may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 toDWDM1705. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 are substantially the same as multi-wavelength upstream optical data signal1743. WDM1713 may function as a circulator when receiving multi-wavelength upstream optical data signal1743 onport1712. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may be received byDWDM1705.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1705 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1705 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the coherent 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

The operation ofheadend1701 may be described by way of the processing of upstream optical data signals received atheadend1701 from a field hub or outside plant. For instance, a multi-wavelength ingress optical data signal, comprising one or more of a 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, EPON optical data signal, and/or GPON optical data signal or a 10GEPN.XGPON may be an upstream optical data signal received onprimary fiber1730 orsecondary fiber1731 depending on the position ofswitch1726.

Multi-wavelength ingress optical data signal1736 may traverse connector1727 andswitch1726, before enteringWDM1723 viaport1737 ifswitch1726 is connected to connector1727. Multi-wavelength ingress optical data signal1736 may traverseconnector1734 andswitch1726, before enteringWDM1723 viaport1737 ifswitch1726 is connected to connector1727.WDM1723 may demultiplex one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, EPON optical data signals, and/or GPON optical data signals from multi-wavelength ingress optical data signal1736.WDM1723 may transmit the one or more EPON and/or GPON optical data signals along GPON/EPON1724 toPON connector1702 viaport1725.WDM1723 may transmit the one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals (e.g., 10 GbE UP1741) out ofport1738 toOPA1742.

The one or more 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may be received byOPA1742. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may comprise 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals. A gain associatedOPA1742 may be based at least in part on a distance that 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals have to travel, similar to that ofBOA1716. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1741 may be amplified byOPA1742, andOPA1742 may output multi-wavelength upstream optical data signal1743 to WDM1713.

WDM1713 may receive the multi-wavelength upstream optical data signal1743 onport1712, and may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 toDCM1708.DCM1708 may perform one or more operations on one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 to compensate for any dispersion that may have been introduced by circuit components (e.g., WDM1713,OPA1742, or WDM1723) or imperfections or issues with an optical fiber (e.g.,primary fiber1730 or secondary fiber1731).DCM1708 may output one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 toDWDM1705. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1709 are substantially the same as multi-wavelength upstream optical data signal1743. WDM1713 may function as a circulator when receiving multi-wavelength upstream optical data signal1743 onport1712. The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may be received byDWDM1705.

The one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may comprise 10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.DWDM1705 may demultiplex the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 into individual optical data signals in accordance with the individual wavelengths of the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706. More specifically, the one or more optical data signals 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1706 may be demultiplexed into twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, each of which may have a unique wavelength.DWDM1705 may output each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals to each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704. Each of the transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may convert a received corresponding 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signal, of the 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals, into a corresponding electrical signal. More specifically, a first transceiver in each of the transponders may convert each of the twenty 10G NRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals into the corresponding electrical signal. Each of the transponders may also comprise a second transceiver that may convert the corresponding electrical signal into a SONET/SDH optical data signal with a corresponding SONET/SDH optical data signal wavelength. In some embodiments, each of the twenty corresponding SONET/SDH optical data signals may have the same wavelength. In other embodiments, each of the twenty corresponding SONET/SDH optical data signals may have unique wavelengths. The twenty transponders of 20×10G NRZ, coherent 100 GbE, 200 GbE, and/or 400GbE UP1704 may transmit the twenty SONET/SDH optical data signals to the MTC on the SONET/SDH optical network connection.

FIG. 18 depicts an access network diagram of an OCML headend and outside plant, in accordance with the disclosure. Atblock1802 the OCML headend may receive one or more first optical data signals from a network. Atblock1804 the OCML headend may combine the one or more first optical data signals. Atblock1806 the OCML headend may generate a second optical data signal based at least in part on applying the combined one or more first optical data signals to a dispersion compensation module (DCM). Atblock1808 the OCML headend may generate a third optical data signal based at least in part on applying the second optical data signal to an optical amplifier. Atblock1810 the OCML headend may combine the third optical data signal with one or more passive optical network (PON) signals into a fourth optical data signal. Atblock1812 the OCML headend may transmit the fourth optical data signal to a field hub.

FIG. 18 may cover the operation of the OCML headend inFIGS. 1, 10, 11, 14, 16, and 17 in the downstream.

FIG. 19 depicts a process of transmitting optical signals with the OCML headend, in accordance with the disclosure. Atblock1902 the OCML headend may receive one or more first optical data signals from a network. Atblock1904 the OCML headend may generate a second optical data signal by combining the one or more first optical data signals. Atblock1906 the OCML headend may generate a third optical data signal by combining the second optical data signal with one or more passive optical network (PON) signals. Atblock1908 the headend may transmit the fourth optical data signal to a field hub. The flowchart inFIG. 19 may cover the operation of the terminal inFIGS. 3, 5, 6, 12, and 15 in the downstream.

FIG. 20 depicts a process of transmitting optical signals with the OCML headend, in accordance with the disclosure. Atblock2002 the OCML headend may receive one or more first optical data signals from a network. Atblock2004 the OCML headend may combine the one or more first optical data signals. Atblock2006 the OCML headend may generate a second optical data signal based at least in part on applying the combined one or more first optical data signals to a dispersion compensation module (DCM). Atblock2008 the OCML headend may generate a third optical data signal based at least in part on applying the second optical data signal to an optical amplifier. Atblock2010 the OCML headend may generate a fourth optical data signal based at least in part on applying the third optical data signal to an variable optical attenuator. Atblock2012 the OCML headend may combine the fourth optical data signal with one or more passive optical network (PON) signals into a fifth optical data signal. Atblock2014 the OCML terminal may transmit the fifth optical data signal to a field hub. The flowchart inFIG. 20 may cover the operation ofFIG. 13 in the downstream.

FIG. 21 depicts an illustrative aggregation node, in accordance with the disclosure. Aggregation node2105 may comprise one or more of a muxponder, ethernet switch or a router. Aggregation node2105 may multiplex one or more 10GNRz, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals received from anyone ofnode2106 . . .node2107. Aggregation node2105 may comprise a10GNRZ, coherent 100 GbE, 200 GbE, and/or 400 GbE transceiver (e.g., trx2115), that receives one or more optical data signals comprising a multiplexed 10GNRz, coherent 100 GbE, 200 GbE, and/or 400 GbE optical data signals.trx2115 may receive these one or more optical data signals over a connection, for example a MDM (e.g., MDM208) and may output one or more 10GNRZ or 40GNRZ optical data signals tonode2106 . . .node2107. For example, aggregation node2105 may transmit streaming video footage, that it received from one or more video servers at an OCML headend (e.g., OCML207), over a 10GNRZ optical data signal. In another example, aggregation node2105 may transmit one or more high bandwidth packets, corresponding to several movie files, tonode2107 over a 40GNRZ optical data signal.

Aggregation node2105 may transmit the one or more optical data signals tonode2106 out oftxr2125 and may transmit the one or more optical data signals tonode2107 out oftxr2135.Node2106 may receive the one or more optical data signals on txr2126 fromtxr2125, andnode2107 may receive the one or more optical data signals on txr2127 fromtxr2135.trx2126 may receive one or more 10GNRZ or 40GNRZ optical data signals and a remote physical device (R-PHY) in node2106 (e.g., R-PHY2116) may convert the one or more optical data signals to a cable signal (e.g., a digital over cable service interface specification (DOCSIS) signal).trx2127 may receive one or more 10GNRZ or 40GNRZ optical data signals and a R-PHY in node2107 (e.g., R-PHY2117) may convert the one or more optical data signals to a cable signal (e.g., a DOCSIS signal). After R-PHY2116 and R-PHY2117 convert the one or more optical data signals to cable signals, one or more devices connected tonode2106 and2107 respectively may receive the cable signals.

Node2106 andnode2107 may transmit cable signals to an OCML headend via aggregation node2105, and aggregation node2105 may receive one or more 10GNRZ and/or 40GNRZ optical data signals corresponding to the cable signals and may multiplex the one or more 10GNRZ and/or 40 GNRZ optical data signals onto an optical fiber. In particular, trx2115 may multiplex the one or more 10GNRZ and/or 40GNRZ optical data signals onto the optical fiber as 10GNRZ, coherent 100G, 200G, and/or 400G optical data signals.Node2106 andnode2107 may be one ofdevice299.

Claims (14)

What is claimed is:

1. An optical communication module link extender (OCML) comprising:

a Dense Wave Division Multiplexer (DWDM) at a headend that is configured to receive one or more first optical data signals from a network, and combine the one or more first optical data signals into a second optical data signal;

a first Wave Division Multiplexer (WDM) at the headend that receives the second optical data signal and outputs a third optical data signal;

a booster optical amplifier, wherein the booster optical amplifier is configured to amplify the third optical data signal and output a fourth optical data signal;

a second WDM at the headend that receives the fourth optical data signal and outputs a fifth optical data signal; and

a third WDM at the headend that receives the fifth optical data signal and outputs a sixth optical data signal.

2. The optical communication module link extender ofclaim 1, further comprising a variable optical attenuator (VOA) communicatively coupled to the second WDM and the third WDM.

3. The optical communication module link extender ofclaim 1, further comprising an optical switch coupled to an output of the third WDM, wherein the optical switch is configured to output the sixth optical data signal on a first fiber or a second fiber.

4. The optical communication module link extender ofclaim 1, wherein the optical switch is further configured to:

receive an input optical data signal, and

output the input optical data signal to a second booster optical preamplifier.

5. The optical communication module link extender ofclaim 4, wherein the second booster optical amplifier is configured to:

amplify the input optical data signal; and

output the amplified input optical data signal to the first WDM.

6. The optical communication module link extender ofclaim 5, wherein the first WDM is further configured to:

receive the amplified input optical data signal from the first WDM; and output the amplified input optical data signal to the DWDM.

7. A method for multiplexing one or more optical data signals, the method comprising:

receiving, by a dense wave division multiplexer (DWDM) at a headend, one or more first optical data signals from a network;

combining, by the DWDM, the one or more first optical data signals into a second optical data signal;

receiving, by a first wave division multiplexing (WDM) at the headend, the second optical data signal the second optical data signal;

outputting, by the first WDM, a third optical data signal to a booster optical amplifier at the headend;

receiving, by the booster optical amplifier communicatively coupled to the first WDM, the third optical data signal;

amplifying, by a booster optical amplifier, the third optical data signal;

outputting, by the booster optical amplifier, a fourth optical data signal to a second WDM at the headend;

receiving, by the second WDM, the fourth optical data signal;

outputting, by the second WDM, a fifth optical data signal;

receiving, by the third WDM, the fifth optical data signal; and

outputting, by the third WDM, a sixth optical data signal.

8. The method ofclaim 7, further comprising:

receiving, by an optical switch, the sixth optical data signal; and

outputting the sixth optical data signal on a first fiber or a second fiber.

9. The method ofclaim 7, wherein the optical switch is further configured to:

receive an input optical data signal, and

output the input optical data signal to a second booster optical preamplifier.

10. The method ofclaim 9, wherein the second booster optical amplifier is configured to:

amplify the input optical data signal; and

output the amplified input optical data signal to the first WDM.

11. The method ofclaim 10, wherein the first WDM is further configured to:

receive the amplified input optical data signal from the first WDM; and output the amplified input optical data signal to the DWDM.

12. A system comprising:

a Dense Wave Division Multiplexer (DWDM) at a headend that is configured to receive one or more first optical data signals from a network, and combine the one or more first optical data signals into a second optical data signal;

a first Wave Division Multiplexer (WDM) at the headend that receives the second optical data signal and outputs a third optical data signal;

a booster optical amplifier, wherein the booster optical amplifier is configured to amplify the third optical data signal and output a fourth optical data signal;

a second WDM at the headend that receives the fourth optical data signal and outputs a fifth optical data signal; and

a third WDM at the headend that receives the fifth optical data signal and outputs a sixth optical data signal.

13. The system ofclaim 12 further comprising:

a variable optical attenuator (VOA) communicatively coupled to the second WDM, wherein the VOA is configured to receive the fifth optical data signal, adjust a power of the fifth optical data signal to a first level, and output a sixth optical data signal.

14. The optical communication module link extender ofclaim 1, wherein the third WDM further receives a gigabit passive optical network (GPON) optical data signal and combines the gigabit passive optical network (GPON) optical data signal with the second optical data signal to create the third optical data signal.

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